Knowledge Base: Hach Product FAQ 

 

1720C Process Turbidimeter

My 1720C displays negative numbers, what should I do?

Try doing a cold start, if that doesn't help the pre-amp boards will need to be replaced.

My 1720C/SS6/old style CL-17 is not sending out the correct 4-20 mA output to my recorder/PLC/SCADA, etc.

First press the REC MIN and the REC MAX keys on the analyzer. The displayed values correspond to minimum and maximum values that will be sent to your receiving instrument (chart recorder, PLC, SCADA, etc.)

If the values do not match the minimum and maximum values that you want, they can be changed easily.

To change the minimum value to 1.0, for example, press 1.0 (be sure to include the decimal point) and then the REC MIN key.

To set the receiving device to display a maximum value of 5.0, for example, press 5.0 (include the decimal) and then REC MAX.

Also verify that the recorder output DIP switch is set correctly. The switch for 4-20 mA should be turned on and all the other switches should be turned off.

My 1720C, Surface Scatter6, or CL-17 Online Analyzer keypad is locked and the instrument will not respond to reset. What can I do?

Disconnect the wires to the 4-20 mA output, and try to reset the system again.

If the analyzer responds, there is likely an electro-mechanical interference in the signal wires.

If the analyzer does not respond, the ribbon cable connecting the keypad to the microprocessor should be replaced.

 

2100N, 2100AN Laboratory Turbidimeters

I'm trying to calibrate a 2100N or 2100AN turbidimeter but keep getting the E01 or E02 error message. What can I do?

An E01 or E02 error message indicates a problem with either the dilution water, or one or more of the standards. Using StablCal standards in sealed vials rarely leads to this type of calibration error. If you are using these standards however, make sure the standards have been well mixed by shaking or inverting repeatedly (with the exception of the <0.1 NTU vial), and that the vials have been oiled.

If using StablCal in bulk bottles, make sure all but the <0.1 NTU standard has been shaken for several minutes before pouring into a sample vial. Allow to sit undisturbed for a few minutes to allow any bubbles to dissipate, then try the calibration again.

If you are preparing your own standards from dilutions of a 4000 NTU stock solution, measure each dilution in the measurement mode. If one standard reads significantly higher or lower than the NTU value of the standard, prepare another dilution from the 4000 NTU stock solution.

If the dilution water reads greater than 0.5 NTU, clean the sample cell using 1:1 hydrochloric acid, then rinse thoroughly with the dilution water. If the dilution water still reads >0.5 NTU, try another source of clean water. Then prepare fresh standards and try the calibration again.

If you are still having problems, try resetting the instrument back to the factory calibration by pressing and holding the CAL key as you turn the instrument on. Read the dilution water and standards in the measurement mode to be sure they read close to what they should, then try the calibration again.

If readings are unstable, it may be necessary to replace the lamp.

I'm trying to calibrate a 2100N or 2100AN turbidimeter using test tubes but keep getting an error message, what is wrong?

The instrument will give error messages based on what the calibration readings should be in the standard 30-mL sample cells. When test tubes are used, the NTU readings will be lower than what they would be in the standard cells due to the shorter pathlength. On the other hand, the <0.1 NTU standard may read higher than 0.5 NTU due to increased scattering from the glass tubes. Both of these situations can cause E01 or E02 error messages.

To use the instrument with these tubes, you can do one of three things:

  1. Calibrate the instrument using the test tubes but ignore the Cal? light. The instrument will still use the calibration you entered to measure your samples.
  2. Calibrate using StablCal in the sealed vials, then read and record the NTU value of StablCal in the small tubes. Prepare a calibration curve of NTU readings in tubes vs. StablCal concentration to determine turbidity of unknowns in the small tubes.
  3. Use different standard concentrations, for instance 40 NTU instead of 20 NTU, for calibration with the tubes. The StablCal standards in small tubes should read at least 60 NTU apart, the 20 NTU standard should read >10 NTU, and the <0.1 NTU standard should read <0.5 NTU to avoid error messages (when read using the default calibration).

If the <0.1 NTU standard in the small tube reads >0.5 NTU using the standard calibration, try cleaning the cell with 1:1 HCl, then rinse thoroughly and fill with <0.1 NTU StablCal standard. Be sure to oil the outside of the tube, and try turning the tube to see if the NTU value reads lower in a different orientation.

If you want to be sure you are using the default (standard) calibration, press and hold the CAL key as you turn the instrument on. This will place the instrument in a cold start condition and reset all factory default settings.

My 2100N or 2100AN turbidimeter is flashing 0.999, 9.99, or 99.9, what can I do?

Press the range key until the light beneath auto range is lit. If a manual range is selected, the instrument will not display above the selected range.

My 2100N or 2100AN turbidimeter display is flashing 9999, what can I do?

The flashing 9999 is displayed when the ratio mode is turned off and the sample turbidity is greater than 40 NTU, or when the measured turbidity is above the range that the instrument can measure. If the measured turbidity is above 40 NTU, the instrument must be in the ratio mode to display the measured NTU value. Look to see if the light next to the RATIO key is on. If you do not see the light, press the ratio key.

If the instrument is in the ratio mode and it still displays 9999, the sample is above the upper turbidity limit for the instrument. The upper limit for the 2100AN turbidimeter is 10,000 NTU. The upper limit for the 2100N turbidimeter is 4000 NTU.

If your sample is above the turbidity range of your instrument, you will have to dilute your sample. Dilution can alter the characteristics of the suspended particles and produce erroneous results, however, so it is best to use an instrument that can measure your sample without dilution.

When necessary, dilute samples using a portion of filtered sample. Deionized or distilled water should not be used for dilution water, because some of the turbidity in the sample may dissolve. Use the Sample Filtration and Degassing Kit (Catalog No. 4397510) for filtering the sample. After dilution and measurement, multiply the displayed result by the dilution factor.

My 2100N or 2100AN Laboratory Turbidimeter does not display 0.000 when no sample is in the instrument. Does it need repair?

The empty cell reading (no sample cell in instrument, lid closed) in a turbidimeter displays stray light in the instrument and is normal. Stray light comes from light that reflects off internal surfaces in the instrument and reaches the detector. Stray light increases over time as dust collects on the optical lenses and other surfaces.

When the stray light reading gets above 0.03 NTU, clean the EPA filter (Catalog No. 3031200) with glass cleaner and a lint-free cloth. If the reading is still high, the instrument should be thoroughly cleaned by the Hach Service Department.

My 2100N or 2100AN Turbidimeter restarts itself randomly. During this time it displays odd numbers, erratic readings, and the lamp icon flashes on and off. What is happening?

This can occur if the lamp flickers momentarily. When the lamp flickers, the instrument responds as if it had been turned off and on, and begins the same diagnostic sequence as when you turn the instrument on. Replace the lamp to correct this problem.

Lamps may begin to flicker as they age. Turbidimeter lamps typically have a life expectancy of 8000 hours, which is approximately equivalent to one year if the instrument is always left on.

What is the wavelength of the USEPA filter used in the 2100N/AN?

This filter has a wavelength range of 400-600 nm. This range is required for compliance with USEPA specifications.

My 2100N Turbidimeter displays E09, which is a printer timeout error, however there is no printer connected to the instrument. What does this mean?

When no printer is connected to the instrument, an E09 error message indicates an electronic problem. The instrument should be serviced by qualified Hach service personnel.

 

2100P Portable Turbidimeter

The 2100P Turbidimeter doesn't read my samples, it only displays a flashing "9.99" or "99.9". What can I do?

A flashing 9.99 or 99.9 indicates that the instrument is in the Manual Range mode and the sample turbidity is above the selected range. There are three Manual Ranges that display either two, one, or no decimal places: 0.00 - 9.99, 10.0 - 99.9, and 100 - 1000 NTU. If the 0 - 9.99 range is selected and the sample turbidity is greater than 9.99, the display will flash 9.99.

When Automatic Range is selected, the number of decimal places changes automatically with the measured turbidity of the sample. Flashing 9's will not appear. To select Automatic Range, press the range key until AUTO RNG appears in the display. The display will stop flashing and show the turbidity of the sample.

Is there a way to reset the 2100P Turbidimeter (Catalog No. 465000) so that it uses the factory settings?

Yes. Restoring the factory settings can be helpful if the instrument was calibrated incorrectly, or if the instrument appears to display values that are significantly far from what is expected.

To restore the factory settings and calibration, follow the steps below:

  1. Turn the instrument off.
  2. Press and hold the DIAG key as you turn the instrument on.
  3. Release DIAG when the software version (a number such as 1.3) disappears from the display. (For models with serial number less than 920300000800, 2100 disappears). CAL? will appear and continue to flash until a user-entered calibration is successfully completed.

This procedure clears any user-entered calibration from memory, and is equivalent to a cold start used on other instruments. The 2100P will then use the factory calibration for measurement. If the reset corrects the problem, calibrate the instrument with StablCal Standards to remove the CAL? from the display.

If the reset does not correct the problem, try replacing the lamp (Catalog No. 4653900). The lamp may become weak over time and fluctuate in intensity, resulting in poor reproducibility and poor accuracy.

 

Accu4 and Steady Stream 4 Turbidimeters

Can I use a Cal-Cube for calibrating my Accu4 or Steady Stream 4 Turbidimeter?

A Cal-Cube is a secondary standard designed for verifying that the calibration of a turbidimeter is correct. It can be used for calibration only if the turbidity values are not being reported to the USEPA.

If your turbidity measurements are reported to the USEPA, use a primary turbidity standard such as formazin or StablCal for calibration.

Why do the light sources in my Accu4 or Steady Stream 4 Turbidimeter have to be replaced as a matched pair?

The LED light sources in these instruments produce an 860 nanometer bandwidth of light at a predetermined voltage. The discrete components can have some variability. The light sources are matched to minimize this variability and ensure the most accurate measured values.

Can I simulate a turbidity sensor signal when troubleshooting the Accu4 or Steady Stream 4 Turbidimeter?

A sensor simulation signal cannot be input directly into the analyzer. However, many instruments have a variety of maintenance and troubleshooting functions in the analyzer menu that will help to isolate a problem.

 

Aquatrend Network

The computer is not seeing the SIO in our Aquatrend network. I downloaded the DataCom software and each time I start it, the message "Aquatrend Not Found" is displayed. The port settings are correct.

There are a couple of possibilities as to why DataCom is unable to find the SIO. First, are you using a cable purchased from Hach or is it one that you have provided? We have seen problems with cables purchased locally by customers.

If it is not a Hach cable you may want to try a different one to see if it is causing the problem. Second, check to make sure there is not a modem or other device using the com port. Try using a different port if possible. You can also try using a different computer if you have one available.

My Aquatrend network seems to be set up properly, but I'm not receiving a 4-20 mA signal from the SOM.

  1. Make sure the SOM is part of the network. Press the Menu key on the Aquatrend interface, select Network Menu, and then select Review Net Connections. Then select List Network Devices, and look to see if the SOM is listed. If it isn't listed, and it can't be found when trying to add it to the network, the SOM needs to be manually unconfigured. After it is unconfigured, add the SOM to the network.
  2. If the SOM is part of the network, make sure the signal from the sensor, such as 1720D turbidimeter, is directed to the correct SOM Analog Output. Press the Menu key on the Aquatrend interface, select Network Menu, and then select Review Net Connections. Then select Recorder to Analog Out. If the correct SOM to sensor connection is shown, make sure the wires in the SOM are connected to the correct output. Pins 1 and 2 of terminal connector J3 are for Analog Out #2, and pins 3 and 4 are for Analog Out #1.
  3. If the networking and analog connections are correct, then go to the Sensor menu. Once there, select Recorder Setup, and choose the correct recorder that has been connected to the SOM. Check the Rec Min and Rec Max settings.
  4. If the Rec Min and Rec Max settings are correct, disconnect the wires on the SOM and connect a Digital multimeter (DDM) to the outputs. Then press the Menu key, and choose Other Device Menu, then select Output. Once there, select Recorder Output #1 or #2, and go through the full scale, half scale and zero scale tests to make sure the SOM is working.

I cannot add my 1720D sensor to the Aquatrend network.

First verify that the configure light (located next to the configure button) on the face of the 1720D is flashing about once a second. If the light is not flashing, verify that the power light is on and that the sensor has power.

If the configure light is not on and the instrument has power, you will need to follow these steps:

  1. Shut the power off to the 1720D sensor.
  2. Push and hold down the configure button (it is critical to keep the configure button pressed down until all the steps are finished).
  3. While pressing down the configure button, turn the power back on to the 1720D sensor.
  4. Keep pressing the configure button and slowly count to 20 after the 1720D sensor power light turns on.
  5. Release the configure button. The configure light should blink about once a second, which indicates that the sensor is ready to be added to the network.

If the sensor still cannot be added to the network, thoroughly check the network wiring. Physically check all of the connections for loose wires. Double check that all network devices are not miswired or cross wired.

 

BARTs (Biological Activity Reaction Tests)

How do I dispose of BART's testers?

Review the Disposal Considerations section of the Material Safety Data Sheet (MSDS) for each product. Because federal regulations can be superceded by local or state regulations, you should consult with your local regulators to ensure you are in compliance for disposal of hazardous chemicals.

I'm using the BART testers, and the bacteria population is given in cfu/mL. What does cfu mean?

cfu stands for "colony forming units". cfu/mL represents the amount of bacterial colonies per milliliter of sample.

 

BODTrak

Where can I find the catalog numbers for the tubing and caps on my BODTrak apparatus?

The catalog numbers for these items are as follows:

Tubing: 2709700

Bottle cap: 4089300

Bottle cap washer: 4081100

Bottle cap stem and tubing: 4081200

How can I remove the old cap from my BODTrak apparatus so that I can put on a new cap (Catalog No. 4089300)?

The tubing may be difficult to remove from the stem of the old cap. Try soaking the tubing and old cap in hot soapy water and try to twist the tubing to remove it. If it still will not loosen, place a flat screwdriver between the cap and the end of the tubing and gently pry the tubing from the old cap.

 

CL17 Chlorine Analyzer

Why does my CL17 chlorine analyzer always read zero, or very low concentrations?

Most likely the flow rate is too low or too high. The optimal flow rate through the colorimeter is 270-300 mL/min.

If the flow rate is too low, color from the previous sample will not be flushed from the colorimeter when the instrument takes the zero measurement for the next reading. The instrument will not see a color difference between the zero and read measurements, and therefore display a zero reading.

If the flow rate is too high, the color that forms in the sample will be flushed from the colorimeter before the analyzer can measure it.

My CL17 chlorine analyzer has the correct flow but is still reading zero, what are the other possible problems?

If the flow rate going through the colorimeter is between 270-300 mL/min, but the instrument reads zero, there are various possible causes:

  • Old tubing
  • Grooves worn on the back side of the peristaltic pump blocks
  • Loose pressure plate on the peristaltic pump
  • Bad photocell, lamp, and/or interference filter
  • A chlorine level well above the analyzer maximum of 5 mg/L. In this case the high level of chlorine will bleach the pink color, turning it clear and causing a zero reading.
  • DPD powder not added to the bottle of Indicator Solution

My CL17 chlorine analyzer is reading correctly, but the pumps are not turning on.

Check to make sure the relays are working correctly by pressing 918 DIAG. Then check the set points and make sure that the alarm is set to LOW and not HIGH.

Our CL17 chlorine analyzer display shows "Sensor Warning". How can we find out what the problem is and what the corrective measures are?

This message indicates that the analyzer has detected something wrong using its internal diagnostics. To see what the error is, push the menu key. Push the down arrow key until you reach the alarm menu, then press enter. Press the down arrow until recall is displayed, then press enter. An error message will be displayed. Look in the instrument manual to find the error message and corresponding correction.

We have an old style CL17 chlorine analyzer that goes through a SIM to a MOD I/O. We need more outputs to hook up additional equipment, is this possible?

Additional output can be added as long as the total impedance of the system does not exceed 500 ohms. If the impedance is over 500 ohms, you can add an additional SOM module to the network, or use a 4 - 20 mA splitter.

How can I connect an older version of the CL-17 chlorine analyzer to our Aqua Trend Network and computer?

You will need to connect the CL17 4-20 mA output to a SIM module 51450-00, which will connect the CL17 to the Aquatrend Network. Then connect a MOD I/O module 57100-00 to the network.

This will take the readings from the Aquatrend and convert them into MODBUS and send them via RS/232 to a serial port on the computer. Finally, the MOD I/O software 57111-00 will take the MODBUS information from the serial port and log it into an Excel spreadsheet.

Does the CL17 Chlorine Analyzer measure free and total chlorine?

Yes, the CL17 measures either free or total chlorine depending on which reagent set is installed in the instrument. The CL17 will not measure both parameters at the same time, however.

Can I change my CL17 Chlorine Analyzer for free chlorine to measure total chlorine and vice versa?

Yes. You will need to install the reagents for either free or total chlorine, and ideally change the reagent tubing.

If the analyzer is due for its annual maintenance, change all the tubing and install the new reagents.

If the analyzer is not due for maintenence, thoroughly flush the lines with deionized water. Then install the new reagents.

My CL17 Chlorine Analyzer buffer solution is brown, what is wrong?

If the DPD Indicator Powder is mistakenly added to the Buffer Solution, rather than the Indicator Solution, it will turn the Buffer Solution a turbid brown color. If this happens, the buffer must be replaced.

What should the color of the reagents for the CL-17 Chlorine Analyzer be?

The Buffer Solution should be clear and colorless. The Indicator Solution, after the DPD powder is added, can vary in color from clear to dark read. The color will vary from lot to lot, but this does not indicate a quality problem, and it will not affect your chlorine results.

My CL17 Chlorine Analyzer came with two extra reagent bottles. What are they for?

In addition to the normal reagent set, the analyzer comes with two bottles of chemicals. One is a small 100 ml dropper bottle of 19.2 N sulfuric acid (Catalog No. 203832). This solution is used for cleaning the analyzers. Instructions for using this solution are in the maintenence section of the instrument manual.

The other reagent is a 29 ml bottle of 0.250 N ferrous ammonium sulfate (Catalog No. 181133). This solution is used to create a zero standard for calibrating the instrument if needed. Instructions for using this solution are located in the calibration section of the instrument manual.

 

COD Reactor

What can I use in place of the COD Reactor (Catalog No. 4560000 or 4560002) that has been discontinued?

The replacement for the COD Reactor used for COD or Test 'N Tube tests is called the DRB200 Reactor, or Digital Reactor Block 200. This reactor comes in three versions that differ in the number and size of tubes the reactor can hold.

All versions hold the 16-mm tubes used for COD, TOC, and Test `N Tube methods. A reducing adapter (Catalog No. HHA155) is available to reduce 20-mm holes to the 16-mm size. One version has two separately controlled heating blocks so that you can use two different temperature settings at the same time.

The Catalog Numbers and main differences between the three versions are given in the following table:

DRB200 Version Heating Blocks 16-mm wells 20-mm wells Catalog No. 110V Catalog No. 220V
1 1 9 2 LTV082.53.30001 LTV082.52.30001
2 1 15 0 LTV082.53.40001 LTV082.52.40001
3 2 21 4 LTV082.53.42001 LTV082.52.42001


My COD Reactor (Catalog No. 4560000 or 4560002) heats but does not reach the 150 oC temperature setting. What can I do?

If the temperature is only a few degrees from 150 oC, try gently adjusting the 150 oC temperature control on the back of the instrument. Be careful to make only small adjustments when turning the temperature control and do not apply force if you feel resistance.

If you have adjusted the temperature control but the reactor still does not reach 150 oC, replace the thermal compound between the heater and block. The thermal compound transfers heat from the heater to the block. When the thermal compound deteriorates, the heating indicator light will turn on and off but the temperature will not reach 150 oC.

You can replace the thermal compound using the COD Block Replacement Kit, Catalog No. 4564900. This kit includes the thermal compound, applicator, wrench, and instructions. To replace the compound remove the block, clean the old compound off the block, apply fresh thermal compound to the bottom of the block, and place the block back in the reactor. You do not need to open the instrument housing to replace this compound.

I spilled reagent in my COD Reactor (Catalog No 4560000 or 4560002) and need to clean it. How can I do this?

If reagent has spilled into the wells of the reactor block, unplug the instrument, place a wet cloth in the well and wipe gently to dissolve and remove the reagent. If the reagent has dried, it may take multiple wipings to remove the reagent and any broken glass.

If reagent has spilled between the reactor block and instrument housing, you can remove the COD block for cleaning, but you will have to apply fresh thermal compound between the block and heater before you place the block back in the reactor. The thermal compound transfers heat from the heater to the block. Whenever the block is removed, the old compound must be scraped off and fresh compound must be applied for the reactor to operate properly.

To remove the COD Reactor block, unplug the instrument and remove the two screws on the top of the block. Use the COD Block Replacement Kit, Catalog No. 4564900, which includes the wrench, thermal compound, applicator, and instructions. Do not remove the instrument housing.

When you have removed the block, clean any spilled reagent from the block with water, and wipe the inside of the block compartment with a wet cloth to remove any spilled reagent.

My COD Reactor (Catalog No 4560000 or 4560002) does not heat at all and the power indicator light is off. What can I do?

If the instrument is plugged in and turned on, check whether the left switch on the front of the instrument is set to infinity or timer. If set to timer, make sure that the time dialed with the timer knob has not expired. If the instrument still does not heat, check the fuses and power connection. Try switching the temperature mode switch to ADJ if set to 150 deg C, or to 150 deg C if set to ADJ. If the heater works in one position but not the other, the switch is faulty.

If the reactor still does not heat, the problem could be caused by faulty electrical components such as switches, thermistors, or circuit board components. The instrument should be evaluated and repaired by a qualified service technician.

What parts are available for the COD Reactor (Catalog No 4560000 or 4560002)?

The following parts are available for COD Reactors made since 1992 with serial numbers ending with 6598 or higher. These parts can be replaced without removing the instrument housing.

4564900 Block replacement kit 4564000 Fuse, 3A, 250V, for 115V operation 3030700 Fuse, 1.6A, ,250V, for 230V operation 3030600 Fuse, 1.6A, 250V, for 230V operation 4560901 Heating Block, 15 16-mm wells 4442400 Knob on front panel (for timer) 4108300 Retainer clip (use when replacing knob) 4560300 Switch, timer and temperature

Any internal parts requiring removal of the instrument housing should only be replaced by a qualified service technician. Parts for instruments made before the serial number given above are no longer available.

 

Conductivity On-line Analyzers

Can I simulate a conductivity sensor signal for troubleshooting my analyzer?

A contacting conductivity sensor can be simulated using fixed resistors. The electrodeless sensor cannot be simulated, but a fixed resistor can be used with the sensor to simulate a conductivity value. Many instrument models have a variety of maintenance and troubleshooting functions in the analyzer menu that will help to isolate a problem.

Can I calibrate my Conductivity Analyzer when the sensor and calibration solution are not at the same temperature?

If the conductivity sensor and calibration solution are at different temperatures, the calibration will be inaccurate. The analyzer will also reject the calibration if a temperature drift is detected. If the calibration is inaccurate, all measuremnts after the sensor is returned to the process will be inaccurate.

 

Dissolved Oxygen Meters and Probes

Can I use the LDO probe with my SensIon6, SensIon8, SensIon156, or SensIon378 meter?

The LDO probes for dissolved oxygen require electronics and software that are not compatible with the SensIon meters. You will need an HQ10 or HQ20 meter to use with the portable LDO probes.

Can I use the docking station from my SensIon6 or SensIon156 meter with my HQ10 or HQ20 dissolved oxygen meter?

The docking station used with the SensIon meters is not compatible with the HQ10 or HQ20 dissolved oxygen meters. Use the LDO docking station (Cat. No. 5183001 or 5183002) with the HQ10 or HQ20 meter.

The docking station allows you to connect the meter to AC power. It also allows you to connect the meter to a computer using an RS232 cable (Cat. No. 4812900). The RS232 cable is not included with the LDO docking station.

How do I clean the sensor on my dissolved oxygen LDO probe?

Wipe the probe with a soft, wet cloth to remove deposits. For stubborn deposits, use a dilute detergent solution, rinse well, and soak in tap water for approximately 10 minutes.

Do not use alcohol, organic solvents or abrasives. These will destroy the sensor.

My dissolved oxygen reading using the LDO probe with the HQ10 or HQ20 meter is significantly higher than my reading from the SensIon meter, why is this?

This is generally seen at dissolved oxygen concentrations greater than 5 mg/L. The reasons for this difference are complex, but are due to lower than actual readings from traditional probes that use gas-permeable membranes.

Membrane probes consume oxygen at the electrode surface, and therefore oxygen from the sample must continually go through the membrane to replenish the oxygen consumed. This is why stirring is important with this type of probe.

The more oxygen in the sample, the more oxygen must go through the membrane. At high concentrations (greater than 5 mg/L O2), these probes consume more oxygen than can be transported through the membrane, resulting in a depletion at the electrode surface.

In contrast, the LDO probe does not have a membrane and does not consume oxygen. An equilibrium between oxygen in the sample and oxygen in the sensor film on the sensor cap is easily maintained, and does not require stirring.

The difference in results between the LDO probe and traditional membrane probes is explained in more depth in the LDO Application Note in the Learning Library.

What is the difference between Continuous Read mode and Push to Read mode on the HQ10 or HQ20 dissolved oxygen meter? Which mode should I use?

During Push to Read mode, a measurement is taken only when the Read key is pressed. This is the default meter setting, and it minimizes power consumption and prolongs battery life.

During Continuous Read mode, a measurement is taken twice per second, requiring continuous power. The meter will operate in continuous read mode for 12-hours on fresh batteries (86,400 measurements), and is useful when you need to continuously monitor a process.

Can I manually calibrate the LDO probe/HQ10 or HQ20 meter rather than using the calibration module?

No, the calibration module that accompanies replacement sensor caps or probes is used to update the software with complex data specific to the LDO sensor cap. Once the cap or probe is installed and the software updated with the calibration module, no other calibration is necessary.

However, if desired, an additional manual calibration using a dissolved oxygen standard or water-saturated air can be completed.

How long does it take the portable LDO dissolved oxygen probe or sensor to polarize?

No polarization time is needed for the LDO probe.

Why do other dissolved oxygen probes require sample stirring, but the LDO probe does not?

Other dissolved oxygen probes consume oxygen during measurement, which depletes the oxygen at the electrode surface. The sample must be stirred to replenish this oxygen, or else the probe will detect lower and lower concentrations and give inaccurate results.

In contrast, the LDO probe does not consume oxygen. An equilibrium between oxygen in the sample and oxygen at the sensor surface is easily maintained without stirring.

How often do I need to replace the sensor cap on my LDO dissolved oxygen probe?

The LDO sensor cap should be replaced once a year.

How do I change the sensor cap on the portable LDO dissolved oxygen probe?

Sensor cap replacement on the LDO probe is required annually or whenever the cap has been damaged or fouled. To remove the shroud, hold the shroud and unscrew the collar. Pull the shroud off of the probe body, then remove the collar.

Dry the sensor cap thoroughly before removing. Unscrew the sensor cap and quickly screw the new sensor cap onto the probe (be sure the new cap is completely dry). Be careful not to touch the optics inside the probe.

Select "O2 setup" in the HQ10 or HQ20 meter setup menu, and update the meter using the module that comes with the new sensor cap (see section 3.2.4 in the instrument manual).

The update module is used to update the meter with data specific to the LDO sensor cap. Once the cap is installed and the meter updated with the module, the probe is ready for use. No stabilization time or calibration is necessary.

What is the difference between Internal Datalogging and Timed Print Interval on HQ10 and HQ20 dissolved oxygen meters? Which one should I use?

Both modes automatically take measurements at timed intervals. Internal Datalogging stores these measurements in the meter until the datalog is full. Once the datalog is full, the meter stops storing data. It will not overwrite any stored data points. The HQ10 and HQ20 meters store up to 500 data points. To conserve batteries, the meter activates the probe only when a measurement is required.

Timed Print Interval uses the docking station to send measurements to a PC or printer, and does not save data points in the meter. The meter will continue to take and send measurements until you turn this feature off. Measurements are not limited by the number of data points, as with Internal Datalogging.

Activate these modes by pressing the datalog key (folder icon) on the keypad. The measurement interval can be set to 15 minutes, 30 minutes, or 1, 4, 8, 24, or 48 hours.

 

Dissolved Oxygen On-line Analyzers

Can I simulate a sensor signal for troubleshooting my Dissolved Oxygen Analyzer?

A sensor signal simulation may be possible depending on which instrument model you have. Please refer to your analyzer instruction manual for details. Many instrument models have a variety of maintenance and troubleshooting functions in the analyzer menu that will help to isolate a problem.

Why do dissolved oxygen membrane sensors have to be operated for 12 hours before calibration?

Membrane sensors need to be polarized prior to calibration to ensure that the electrode signal is stable. If the sensor is not polarized, the measured concentration will not be accurate and the reading will drift.

What is an LDO Dissolved Oxygen Probe?

LDO is an abbreviation for Luminescent Dissolved Oxygen, which uses an innovative technology for measuring dissolved oxygen in water. The sensor requires minimal maintenance because it has no membrane, does not require polarization, and rarely needs calibration.

Use the LDO Probe with the sc200 Controller for an accurate, low maintenance system for continuous dissolved oxygen measurements.

 

DR/2000 and DR/2010 Spectrophotometers

I'd like to measure Absorbance or Percent Transmittance (%T) only with the DR/2000 or DR/2010 Spectrophotometer. How can I do this?

When the instrument displays "Method #" or "Enter Program #", press 0 and then ENTER. Adjust the wavelength dial to the desired wavelength. The instrument will then read and display your sample color in absorbance units. To read Percent Transmittance, press SHIFT and then %T.

My DR/2000 Spectrophotometer (Catalog No. 4480000) restarts itself and goes into the self-test mode. Sometimes this happens when I press READ or ZERO. What can I do?

This problem will occur if there is a bad connection between the instrument and Battery Eliminator, or if the batteries are weak. If using batteries, replace them with a new set of D-size alkaline batteries.

If using the Battery Eliminator (Catalog No. 4765200 or 4765100), the most common problem is a bad connecting jack on the instrument. To check the connection, move the cord back and forth near the connecting jack on the instrument. If the instrument shuts off when the cord is moved, the connecting jack (Catalog No. 4642700) should be replaced. This is not difficult to replace, but should be done by a qualified service technician. Alternatively, you can use six D-cell alkaline batteries with the battery holder (Catalog No. 4486600) in place of the Battery Eliminator.

To check whether the Battery Eliminator is good, use a voltmeter to check the voltage coming from the connector that plugs into the instrument. Make sure the switch on the bottom of the eliminator is set to the corresponding outlet voltage that you are using (115V or 230V). Place one probe from the voltmeter on the very end of the pin connector, and the other probe near the base of the pin, near the black cord. There should be at least 7 Volts coming from the Battery Eliminator when it is plugged into an electrical outlet.

DR/2000 shows "EEE" in the wavelength field

This may indicate a minor problem such as turning the instrument on with the lid open, or it may be more serious. To clear the EEE, press the shift key, release, then press the configure key. Then use the arrow keys to scroll to RESET WARNINGS and press ENTER.

The display will show "Completed". Press the method key to return to your program. The wavelength should appear where the EEE was. If the EEE keeps recurring, the instrument will need to be repaired.

A number is flashing or blinking on the display of my DR/2000 Spectrophotometer. What does this mean?

A flashing number on the display means that the concentration of your sample exceeds the range for your test. The number that is shown is the upper limit that the instrument can display for the test you are using. Start with a fresh sample, dilute it with deionized water, and repeat the test.

If the display flashes again, you will need to start over with a larger dilution. If the displayed number does not flash when the diluted sample is measured, multiply the displayed concentration by your dilution factor to find the concentration of your sample before dilution.

Alternatively, choose a higher range procedure for the parameter you are measuring (if available). Multiple ranges are offered for many Hach methods.

My DR/2000 Spectrophotometer (Catalog No. 4480000) is making a high-pitched noise. What is wrong?

This noise may be a result of a bad power connection from the Battery Eliminator to the instrument, or it may be more serious.

If using the Battery Eliminator (Catalog No. 4765200 or 4765100), check the connection to the instrument by moving the cord back and forth near the connecting jack on the instrument. If the instrument shuts off when the cord is moved, the connecting jack (Catalog No. 4642700) should be replaced. This is not difficult to replace, but should be done by a qualified service technician. Alternatively, you can use six D-cell alkaline batteries with the battery holder (Catalog No. 4486600) in place of the Battery Eliminator.

To check whether the Battery Eliminator is good, use a voltmeter to check the voltage coming from the connector that plugs into the instrument. Make sure the switch on the bottom of the eliminator is set to the corresponding outlet voltage that you are using (115V or 230V). Place one probe from the voltmeter on the very end of the pin connector, and the other probe near the base of the pin, near the black cord. There should be at least 7 Volts coming from the Battery Eliminator when it is plugged into an electrical outlet.

If the Battery Eliminator is working properly and the connection is good, or if you are using batteries but still hear the noise, the circuit board must be replaced. The instrument must be repaired and factory-calibrated by the Hach Instrument Repair Department.

The display on my DR/2000 or DR/2010 spectrophotometer shows "LAMP OUT", but I know the lamp is on. What is wrong?

Remove any adapters from the cell compartment such as for AccuVac vials or Test 'N Tubes and try zeroing the instrument. If the lamp out message does not appear, the adapter was likely in the cell compartment in the wrong orientation and was blocking the light beam.

If the message does not appear with an empty cell compartment, but does appear when zeroing or reading a sample, the lamp may be weak and should be replaced (Catalog No. 4664700).

If you just replaced the lamp but the display still shows "LAMP OUT", check to see that the lamp was installed properly, and reinstall if necessary. The lamp assembly should be pushed all the way down in the lamp channel and against the side with the small opening. The V-shaped light slit on the lamp assembly should face the opening. The tube-shaped sleeve and screw should hold the assembly firmly in place.

I see a "Low Battery" message on my DR/2010 when using AC power. What does this mean?

This message may appear when there is poor electrical contact between the power supply and the instrument.

Follow these steps to make sure there is a good connection:

  1. Unplug the power supply from the electrical outlet.
  2. On the connector that plugs into the instrument, gently pull the pins slightly toward the outer ring using a needle-nose pliers.
  3. Plug the connector back into the instrument. There should now be good electrical contact between the power supply and the instrument.
  4. Plug the power supply back into the electrical outlet, and turn the instrument on.

The "Low Battery" message should not appear. If it does, replace the power supply (Cat. No. 4934600).

I have an old DR/2000 Spectrophotometer with version 2.1 or 2.2 software. When I turn it on it shows only "Memory Error". What can I do?

When the display shows Memory Error, an electrical problem such as low voltage or an electrostatic discharge has caused a problem with the instrument memory. Disconnect power to the instrument by unplugging the Battery Eliminator at the back of the instrument. If using batteries, disconnect the battery cable. Then reconnect the power. If the Memory Error message does not appear, the instrument will now operate properly.

If the message is displayed after power is restored, additional investigation is required. If using batteries, install new D-size alkaline batteries. If using the Battery Eliminator, disconnect it and install six D-size alkaline batteries. If the instrument returns to normal operation, the Battery Eliminator should be replaced.

If Memory Error still appears with new batteries, perform the reset procedure as follows:

  1. Turn the instrument on and press and release the SHIFT key, then the CONFIG key.
  2. Press the number 8 three times and then press ENTER. The software version will be displayed (either V2.0 or V2.2).
  3. Press the SHIFT key and then the CONFIG key.
  4. Press the number 8 three times.
  5. Press ENTER and immediately press the numbers 3, 5, and 7. These numbers must be entered within 2 seconds of pressing ENTER.
  6. Turn the instrument off and back on. The factory settings should now be restored.

I have an old DR/2000 Spectrophotometer with version 2.1 or 2.2 software. When I turn it on it shows only "Memory Error W". What can I do?

The Memory Error W is a very serious error and indicates that the instrument has lost important data from its memory. The data is located on a calibration data label that is specific to your instrument (this label applies only to software versions 2.0 and 2.2). The calibration data label should be on the front page of your instrument manual, or inside the instrument lid.

The lost data can be reentered into the instrument only if you have the calibration data label. If you do not have this label, there is no way to repair or use the instrument. Hach Company does not have records of the numbers on these labels.

If you have the calibration data label, recalibrate the instrument by following these steps:

  1. Turn the instrument on and press and release the SHIFT key, then the CONFIG key.
  2. Press the number 8 three times.
  3. Press ENTER and immediately press the numbers 3, 5, and 0. The display will show "Method #". Note: If you don't enter the 3, 5, and 0 within 2 seconds of pressing the ENTER key, the instrument will display the software version.
  4. Turn the power off and then on again.
  5. Press SHIFT and then CONFIG.
  6. Press the number 8 three times.
  7. Press ENTER and immediately press the numbers 3, 5, and 9. The display should show "01-255".
  8. Locate data #01 on the calibration data label. Enter the three-digit number to the right of the #01. (Do not press ENTER). The display will show 02-255.
  9. Enter the number to the right of #02 on the calibration data label.
  10. Continue adding the rest of the numbers on the calibration data label until all 34 numbers have been added. The display should show "Method #" when finished.

Your instrument has been recalibrated. Recheck that all numbers were entered correctly by following these steps:

  1. Turn the power on and then on.
  2. Press SHIFT and then CONFIG.
  3. Press the number 8 three times.
  4. Press ENTER and immediately press the numbers 3, 5, and 9. The display should show "01-(# from your label). Make sure the number shown on the display matches the number on the calibration data label for the first data point.
  5. If this number is correct, press ENTER.
  6. If the number is not correct, enter the correct number, but do not press ENTER.
  7. Continue checking the rest of the numbers until they match the numbers on the label.
  8. Turn the instrument off and then on. The instrument should now be ready for operation.

My DR/2010 Spectrophotometer is plugged into an electrical outlet but will not turn on. What can I do?

First check to see if the problem is with the DR/2010 battery eliminator/power supply (Catalog No. 4934600).

Battery Eliminator Voltage
Check the voltage coming from the battery eliminator as follows:

  1. Plug the battery eliminator into an electrical outlet.
  2. Unplug the battery eliminator from the back of the DR/2010. Notice the 5 pins inside the connector.
  3. Position the connector so the 5 pins form a half-circle pointing down. In this orientation, the pin on the very left is #1 and the pin on the right is #5.
  4. Using a voltmeter, place one probe on pin #3 (ground) and the other on pin #5. There should be at least 7 volts coming from the power supply.

If there is less than 7 volts, the battery eliminator should be replaced. Note: Pin #1 is used for recharging the rechargeable batteries. There should be 10 volts between pin #1 and pin #3.

Battery Eliminator Connection If the battery eliminator is good, make sure there is good electrical contact between the power supply and the instrument as follows:

  1. Unplug the power supply from the electrical outlet.
  2. On the connector that plugs into the instrument, gently pull the pins slightly toward the outer ring using a needle-nose pliers.
  3. Plug the connector back into the instrument. There should now be good electrical contact between the power supply and the instrument.
  4. Plug the power supply back into the electrical outlet, and turn the instrument on.

If the battery eliminator is good and the electrical connection is good, but the instrument will not power on, the instrument most likely has a bad keypad or a bad circuit board. Contact your dealer or the Hach Instrument Repair Department to repair the instrument.

Where can I find part numbers for the Pour-Thru cell used with the DR/2000 and DR/2010 Spectrophotometers?

Replacement parts for the 1-inch Pour-Thru cell (Catalog No. 4521500) are as follows:

Catalog No. Description
1361700 Window (2)
1634700 O-ring, window (2)
4883400 Glass Funnel
4521700 Fitting, elbow (2)
959714 O-ring, fitting (2)
1541200 Gasket, top plate
1906100 Stand Assembly
1906200 Overflow pipe
517937 Tubing, Tygon, 1/8" ID, 1/32" wall (6 ft)
56018 Tubing, drain, 1/4" ID, 3/32" wall (12 ft)

What can I use in place of the rechargeable battery (Catalog No. 4518500) that is no longer available for the DR/2000 or DR/2010 Spectrophotometer?

Use six alkaline D-cell batteries (Catalog No. 1149454) with the battery holder (Catalog No. 4486600) in place of the rechargeable (lead-acid) battery. Install as follows:

  1. Remove the battery compartment cover from the bottom of the instrument.
  2. Install six alkaline D-cell batteries in the battery holder.
  3. Connect the cable from the battery compartment in the instrument to the connector on the battery holder. Place the holder with batteries in the compartment.
  4. Replace the battery compartment cover, and return the instrument to the upright position.

Note: Nickel-cadmium D-cell batteries cannot be used. They do not supply enough voltage for proper operation.

Does Hach still service the DR/2000 Spectrophotometer?

Hach services DR/2000 Spectrophotometers (Catalog No. 4480000) that have software version 3.0 or greater. To find the software version of your instrument, open the lid and look in the upper right corner of the label. The software version is the same as the Rev. number. Instruments with software versions less than 3.0 cannot be upgraded to a higher version.

If your DR/2000 is a version 3.0 or higher, it can be serviced provided parts are still available. The keypad (Catalog No. 4480300) is no longer available. If your instrument needs a new keypad, it cannot be repaired.

A 50 mg/L silica standard solution reads low, for example 42 mg/L SiO2 on one DR/2000 instrument, but 50 mg/L SiO2 on another instrument. What is wrong?

The HR silica test is sensitive to the wavelength setting. Adjust the wavelength calibration as described in the lamp replacement section of the instrument manual, and repeat the test. If the results are still low (or high), try replacing the lamp and repeat the wavelength calibration adjustment.

Is there a way to check the accuracy of the wavelength setting in the DR/2000 or DR/2010 Spectrophotometer without using the 808 nm calibration filter?

A wavelength or lamp calibration adjustment should be performed whenever the lamp (Catalog No. 4664700) is replaced. This adjustment is also useful when the accuracy of the instrument is in question. For example, if results using standard solutions are not correct, or if a wavelength-sensitive method such as HR Silica or the ammonia Nessler method is used, this adjustment will verify that the instrument is using the correct wavelength setting.

The 808 nm Calibration Filter Assembly (Catalog No. 4664600) should be used to make this adjustment. If this filter is not available, however, a visual check of the color of the light beam as it shines through the sample compartment can indicate if there is a significant problem with the wavelength setting.

Visual Check at 577 nm
Follow these steps to visually determine if your instrument is out of calibration:

  1. Make sure the instrument is in the Constant On lamp mode:

    DR/2000: Press SHIFT, then CONFIG. If the display shows "Momentary", press the ENTER key to display "Constant On". Press the METHOD key to exit the configure mode.

    DR/2010: Press SHIFT, then SETUP. The display will show "Autogroup: Off (or On)". Press the DOWN ARROW key until the display shows "Lamp: Momentary" or "Lamp: Constant On". If "Momentary" is displayed, press ENTER and then the DOWN ARROW key to display "Constant On". Press ENTER and then EXIT.
  2. Turn the wavelength dial until the display shows 577 nm.
  3. Open the sample compartment cover and insert a strip of white paper that is approximately one inch wide and several inches long into the compartment.
  4. Look for a yellow spot of light on the paper. If the light does not appear yellow, turn the wavelength knob until the light appears yellow. The yellow color should appear between 573 nm and 581 nm.
  5. If the yellow color is observed between 573 and 581 nm, the wavelength setting is acceptable. If the yellow color is observed outside of the 573 to 581 nm range, the wavelength calibration should be adjusted using the 808 nm calibration filter.

 

DR/2400 and DR/2500 Spectrophotometers

I have a lot of reagents for 25-mL of sample, but my new instrument uses 10-mL powder pillows. Can I use the 25-mL pillows with my new spectrophotometer?

Reagents for many methods used with Hach spectrophotometers were reduced at one time from a 25-mL to 10-mL size to minimize reagent consumption and disposal costs. If you have reagents for a 25-mL sample size but your new spectrophotometer uses 10-mL reagents, you can use the 25-mL reagents with your new spectrophotometer for all but a few methods.

Do not use 25-mL powder pillows in place of 10-mL pillows for the following tests:

  • Nitrate tests using NitraVer5 or NitraVer6 powder pillows
  • Zinc tests using ZincoVer5 powder pillows

When substituting 25-mL powder pillows for 10-mL pillows, be sure to add the 25-mL reagents to 25 mL of sample, rather than to 10 mL sample.

Do not use 25-mL reagents with Test 'N Tube methods unless they are specified in the procedure.

What is the difference bewteen the DR/2400 and DR/2500 Spectrophotometers?

Both instruments are similar in design, and use a touchscreen to navigate through the instrument software. The DR/2400 is designed for field use, and can operate using batteries or AC power. The DR/2500 requires AC power (must be plugged into an electrical outlet), and has more options for laboratory use.

The following features are available on the DR/2500 instrument that are not available on the DR/2400 Spectrophotometer:

  • pH electrode: Instead of using a pH meter, plug a 5-pin pH electrode into the back of your DR/2500 instrument and read your pH values on the touchscreen display.
  • Advanced software: Scan absorbance values over a wavelength range, or measure absorbance at one wavlelength for a timed period.
  • More sample cell options: The DR/2500 can hold a 1-inch square cell, and can hold any round sample cell with a 1 inch (25 mm) diameter or less. The DR/2400 cannot hold a 1-inch square cell. It can hold 1-inch (25 mm) round cells, and COD and TNT vials (16 mm). Both instruments can hold 1-cm square cells.
  • Less sample cell adapters: The DR/2500 uses one adapter for all round sample cells. The DR/2400 requires a separate adapter for TNT and COD vials as well as for the plastic multipath cell used in many high range methods. Both instruments require an adapter for Pour-Thru cells, and 1-cm square cells. Sample cell adapters are not interchangeable between the DR/2400 and DR/2500 instruments.
  • Wider wavelength range: The DR/2500 wavelength range is 365 to 880 nm. The DR/2400 wavelength range is 400 to 880 nm. Three tests are available on the DR/2500 that are not available on the DR/2400 instrument because of this difference: Nitrate, Total Nitrogen, and ULR COD.

The DR/2400 Spectrophotometer underwent an optical update in late 2003 that allowed the THM (trihalomethane) test to be incorporated into the software. The THM test is not available on the DR/2500 Spectrophotometer.

The display on my DR/2400 or DR/2500 Spectrophotometer is blank, but the instrument appears to be on because I can hear it beep, or see the display change slightly when it is turned on. What can I do?

The instrument display may appear to be blank if the Display Contrast is not adjusted to the correct level. Use the up and down arrow keys to change the Display Contrast to a visible level.

My DR/2400 or DR/2500 Spectrophotometer fails the wavelength calibration when I turn it on and displays "Lamp Failure". What can I do?

The DR/2400 and DR/2500 Spectrophotometers perform a wavelength calibration adjustment each time they are turned on. Each instrument uses a combination of LED's and a tungsten lamp. During the adjustment, each light source is turned on. If any light source is burned out, the instrument will display "Lamp Failure".

If the instrument displays "Lamp Failure", the lamp module or illuminator module (Cat. No. for DR/2400: 5945600, for DR/2500: 5905900) must be replaced. This can be replaced by removing the module from the bottom of the instrument and inserting a new module. Step-by-step instructions and a tool for removing the screws are included with new modules.

How do I replace the lamp in my DR/2400 Spectrophotometer?

A combination of light sources, such as a tungsten lamp and LED's, are used to generate light over the instrument's full wavelength range. The light sources are designed to provide years of reliable use. In the event that one of the light sources fails, the entire Lamp Module must be replaced.

Lamp Module part numbers:

For DR/2400s with serial numbers less than 030900002600, please use part number 5945600.

For DR/2400s with serial numbers 030900002600 and greater, please use part number 5964800.

To replace the Lamp Module:

  1. Disconnect the power supply and RS-232 cable if connected.
  2. Place the instrument upside down on a padded surface.
  3. Open the battery cover by depressing the ribbed tab and sliding the battery cover off of the instrument. Remove the batteries.
  4. Remove the two screws that secure the battery compartment using the T10 L-Key tool (Cat. No. 5911700) supplied in the Module Replacement Kit.
  5. Gently pull the battery compartment out just far enough until you can turn it over and rest the compartment on the instrument bottom. Do not twist or strain the power ribbon.
  6. Remove the two screws that secure the Lamp Module, and set them aside to avoid dropping them into the module slot.
  7. Grasp the tab and pull the module out of the instrument.
  8. Insert the new Lamp Module and make sure it is fully inserted before installing the screws.
  9. Insert the two screws and tighten to secure the module.
  10. Gently place the battery compartment back in the instrument, insert the two screws and tighten to secure the compartment.
  11. Replace the batteries and battery cover.
  12. Return the instrument to the upright position and restore power. No calibration is necessary for the lamp module.

How do I replace the lamp in my DR/2500 Spectrophotometer?

A combination of light sources, such as a tungsten lamp and LED's, are used to generate light over the instrument's full wavelength range. The light sources are designed to provide years of reliable use. In the event that one of the light sources fails, the entire Illuminator Module (Catalog No. 5905900) must be replaced.

To replace the Illuminator Module:

  1. Disconnect the power supply, remove the sample cell holder, and disconnect any cables.
  2. Place the instrument upside down on a padded surface.
  3. Remove the three screws that secure the module using the T10 L-Key tool (Cat. No. 5911700) supplied in the Module Replacement Kit.
  4. Turn the instrument over and push on the cell holder cavity to remove the illuminator module.
  5. Insert the new illuminator module from the bottom of the instrument. Make sure the connector pins on the module line up with the connector inside the instrument. Do not force the module in place.
  6. Insert the three screws and tighten to secure the module.
  7. Return the instrument to the upright position and restore power and ot
  8. her cable connections. No calibration is necessary for the illuminator module.

My DR/2400 or DR/2500 Spectrophotometer fails the wavelength calibration when I turn it on and displays "Out of Alignment". What can I do?

The DR/2400 and DR/2500 Spectrophotometers perform a wavelength calibration adjustment each time they are turned on. This adjustment uses a mercury lamp in the DR/2500 and didymium filter in the DR/2400 instrument to adjust the wavelength settings to an accuracy of +/- 1 nm.

If the instrument displays "Out of Alignment", some wavelengths may no longer be targeted on the detector, giving invalid measurements. Please contact your dealer or the Hach Instrument Repair Department to repair the instrument.

Can I use the Pour-Thru cell for testing any parameter with my DR/2400 or DR/2500 Spectrophotometer?

Most parameters can be tested using the 1-inch Pour-Thru Cell, however there are some important exceptions. The Pour-Thru Cell cannot be used to measure the following parameters:

  • Aluminum (ECR method), Arsenic
  • Barium, Boron (Carmine method)
  • Cyanuric Acid
  • Fluoride, Formaldehyde
  • Lead (LeadTrak method)
  • Mercury
  • Nickel (Heptoxime method), HR Nitrite
  • PCB, Phenols, Potassium
  • Selenium, Silver, Suspended Solids, Sulfate, Surfactants
  • TPH
  • Volatile Acids
  • Zinc

The following Hach methods require extra rinsing when using the Pour-Thru Cell:

  • Aluminum (Aluminon method)
  • Chlorine Dioxide, LR (Chlorophenol Red method), Cobalt (PAN method), Copper (Porphyrin method)
  • Hardness (Calmagite method)
  • Manganese, LR (PAN method)
  • Nickel (PAN method), Nitrate, MR and Nitrate, HR (Cadmium Reduction method)

If measuring Ammonia or TKN (Total Kjeldahl Nitrogen), clean the Pour-Thru Cell periodically by pouring a few sodium thiosulfate pentahydrate crystals into the cell. Let stand for a few minutes, then rinse well with deionized water.

My DR/2500 Spectrophotometer will not turn on. What can I do?

First check to see if the problem is with the instrument or the power supply.

Power Supply (Catalog No. 5910700)
Check the voltage coming from the power supply as follows:

  1. Plug the power supply into an electrical outlet.
  2. Unplug the power supply from the back of the DR/2500.
  3. Using a voltmeter, place one probe inside the round connector and the other on the outside of the connector. There should be 9 volts coming from the power supply.

If there is less than 9 volts, the power supply should be replaced.

Instrument
If the power supply is good, you can try resetting the instrument as described below, or contact Hach Technical Support.

Instrument Reset
The instrument reset button can be accessed through a small pin hole in the bottom of the instrument.

  1. Turn the instrument upside down to look for the reset button hole. It is only large enough to fit a straightened paper clip. (Note: instruments manufactured before February 2003 do not have this hole).
  2. Disconnect the instrument from the power supply.
  3. Insert one end of a paper clip into the reset hole and push until you feel the clip contact the reset button.
  4. Press and hold the reset button using the paper clip while reconnecting the power supply. Release the button.
  5. Turn the instrument on using the power button.

Are the square sample cells from my previous model spectrophotometer compatible with the DR/2500 or DR/2400 which uses round cells?

The DR/2400 and DR/2500 instruments were calibrated using round cells, therefore round cells should be used for sample measurements. Square cells have a slightly longer pathlength and will give higher than actual results. If you want to use up 25 mL reagents that you already have, you can use 25-mL round sample cells with most tests.

How do I clean the touchscreen display on my DR/2400 or DR/2500 Spectrophotometer?

Use a soft, damp cloth to wipe the instrument and the touchscreen. Use diluted glass or window cleaner to remove stubborn deposits from the touchscreen. Do not use strong solvents.

Each time we turn on the DR/2400 spectrophotometer, the date and time are incorrect and need to be set again. How can we correct this problem?

The 3 D-cell alkaline batteries must be in the battery compartment for the clock to keep its setting.

 

DR/4000 Spectrophotometer

What are the acceptable limits for the drift check procedure as described in section 11.2.5 of the DR/4000 instrument manual?

At 546.1 nm, the drift should be less than 0.001 absorbance for any 15 minute interval. The drift in the UV range and above 1000 nm may be slightly higher.

What is the expected life of the lamps for the DR/4000?

The average life of the DR/4000 tungsten or deuterium lamp is estimated at 1000-2000 hours. Turning the instrument on and off frequently may shorten this time.

What does a "low battery" message mean on the DR/4000 spectrophotometer?

Check to see if date is correct in the display. If the date is correct, turn the instrument off and on. If a snap or crackling noise is heard, the on/off switch needs to be replaced (Cat. No. 46639-00). This is not difficult to do; it can be replaced by yourself or by the Hach service department.

If the date is incorrect, this indicates a more serious electronic problem and requires repair by Hach service.

My DR/4000 spectrophotometer displays 24 or 26: monochromator or 21 or 22: lamp mirror error, what is wrong?

The monochromator 24 or 26 error message indicates that not enough light is getting to the detector. 24: monochromator indicates a lower light condition than 26: monochromator. Replace the lamp if it has not been replaced recently; lamps can loose intensity over time without burning out.

If the lamp was just replaced, check to see if the wires from the lamp are in the light path or touching the mirror. If so, tuck the wires out of the way of the light beam and away from the lamp. If the visible lamp was replaced, check to be sure the base of the lamp bracket is fully in the recessed area; if not completely in the recessed area the lamp will be mounted at a slight angle.

If the lamp has been replaced and is installed correctly but you still get the error message, the instrument will need to be serviced.

I just replaced the UV lamp in my DR/4000 but still get the UV lamp out message. What is wrong?

This can happen if the UV lamp is installed in the wrong orientation. Be sure the metallic side of the lamp faces the mirror. If it is in the correct orientation, it is possible that the lamp is bad or that the instrument requires service.

What printer can I use with the DR/4000 Spectrophotometer?

The Kyoline Thermal Printer, Catalog No. A70P021 (115V) or A70P020 (230 V), can be used with the DR/4000 Spectrophotometer. Other serial or parallel printers can also be used. The DR/4000 is not compatible with USB printers.

Kyoline Printer Settings:
To set up the Kyoline Printer for use with the DR/4000, set the dip switches on the printer as follows:
SW1: 1 (ON)
SW2: 1 (ON)
SW3: 0 (OFF)
SW4: 0 (OFF)
SW5: 1 (ON)
SW6: 0 (OFF)
SW7: 1 (ON)
SW8: 0 (OFF)

DR/4000 Settings:
Press the SETUP key on the DR/4000 keypad, then SERIAL I/O soft key. Change the settings as follows:
BAUD: 9600
BITS: 8
PARITY: None
OUTPUT: On

Press the SETUP key on the DR/4000 keypad, then PRINTER OPTIONS soft key. Change the print settings as follows:
SELECT PRINTER: Epson Dot Matrix
FORMAT: Block
PAGING: Manual

To print data from the DR/4000 Spectrophotometer, press the print key when data is displayed or recalled.

I just replaced the lamp in my DR/4000 and now the instrument will not power on. What is wrong?

Make sure the lamp compartment cover snaps in place when it is put back on. There is a safety feature that does not allow the instrument to power on when this cover is removed.

With the carousel module in the DR/4000 Spectrophotometer, I see a NO MODULE message when I press Start. What is wrong?

This can happen when the plastic adapter that holds the sample cells is not seated properly in the module. Push the adapter down while turning until you feel it drop further onto the spindle. Then press Start. The instrument should start taking measurements and display the results.

 

DR/820, DR/850, and DR/890 Colorimeters

How do measure Absorbance or %T with the DR/820, DR/850, or DR/890 Colorimeter?

Enter the first two numbers of the wavelength you wish to use as the program number. Then press the ABS %T key to change between absorbance and % transmittance.

For example, the DR/820 Colorimeter has one color filter with a wavelength of 520 nm. Press PRGM, then 52 and ENTER to measure absorbance with this instrument.

The DR/850 Colorimeter has two filters with wavelengths of 520 nm and 610 nm. Press PRGM, then 52 to measure absorbance at 520 nm, or 61 to measure absorbance at 610 nm.

The DR/890 Colorimeter has wavelengths of 420, 520, 560, and 610 nm. Press PRGM, then 42, 52, 56, or 61 to measure absorbance at 420, 520, 560, or 610 nm with this instrument.

The word LIMIT is flashing on my DR/820, DR/850, or DR/890 Colorimeter. What does this mean?

A flashing LIMIT indicates that the measured concentration is outside of the specified range that the instrument can display.

If the display shows a number such as 2.20 when LIMIT is flashing, this means the concentration of your sample exceeds the range for your test. Start with a fresh sample, dilute it with deionized water, and repeat the test. If LIMIT flashes again, you will need to start over with a larger dilution. If LIMIT does not appear, multiply the displayed concentration by the dilution factor to find the concentration of your sample before dilution.

If the display shows 0, 0.0, or 0.00 when LIMIT is flashing, this means the instrument is seeing the sample as less concentrated than the blank. There may several possibilities why this might happen:

  1. The concentration of the sample is zero or below the detection limit of the instrument. If this is the case, the instrument may be reading slightly below zero relative to the blank, but within the +/- 0.005 absorbance units specified for the instrument. If possible, use the same sample cell for the blank and the sample. This minimizes any measured differences due to optical differences between the cells.
  2. A Reagent Blank Correction was entered into the instrument, and the measured concentration is less than the reagent blank value. The instrument subtracts the reagent blank value from each measured concentration.
  3. There is turbidity in the sample that dissolves or paritally dissolves after adding the reagents. In this case the instrument is measuring a decrease in turbidity rather than a change in concentration. Either filter the sample, or adjust the pH of the blank so it is the same as the sample after reagents are added.
  4. There is color in the sample that changes with a change in pH after the reagents are added. Adjust the pH of the blank so it is the same as the sample after reagents are added.
  5. The instrument was zeroed with the blank when it should have been zeroed with the sample. Some procedures, such as for ozone, may instruct you to zero on the sample and measure the blank. This is opposite from most procedures. Check your procedure to be sure you are following it correctly.

My DR/800 colorimeter will not power on when I press the on/off button, what should I do?

Try replacing the batteries with new alkaline batteries, and make sure the batteries are installed in the proper orientation. If this does not help, it is likely that the keypad is not functioning properly, and the instrument should be sent in for repair.

The results using my DR/820, DR/850, or DR/890 colorimeter do not match an outside lab's results, what can I do?

Be sure the results from the lab are reported in the same chemical form that is displayed on the colorimeter, because different conversions are used for the different forms.

For instance, if the outside lab reports results for nitrate as nitrogen (NO3-N), be sure the instrument display shows NO3-N and not NO3. Results reported as NO3 will be 4.4 times the result as NO3-N due to the weight difference between nitrate and nitrogen. Press the CONC key to change the displayed form.

Phosphorus is another common parameter where labs commonly report results as P, but the default form on Hach instruments is as PO43-. A result as PO43- will be 3 times the result as P.

What does Standard Adjust mean in the DR/820, DR/850, or DR/890 Colorimeter procedures? Should I use it?

Standard Adjust is a feature that uses a standard solution to slightly adjust the factory calibration in the intrument software. For example, if a DR/890 instrument displayed 0.96 mg/L when a 1.00 mg/L standard solution were placed in the instrument, the Standard Adjust feature would make the instrument display 1.00 mg/L.

Calibration of the instrument at the factory is very accurate, however some methods have more variability due to user technique and reagent variability. Standard adjust is recommended for those methods, such as nitrate and sulfate, for the best accuracy.

Limits are programmed into the instrument to reject adjustments that are too far from the measured value. Typical limits for standard adjustment are 10-20%, but can be more depending on the method. These limits ensure that if a standard solution were prepared incorrectly, the instrument would reject the adjustment.

For example, if a 1.00 mg/L standard solution were placed in the instrument, and the displayed value were 0.77 mg/L, the instrument would likely not allow you to force it to read 1.00, because that would change the concentration by more than 20%. If this happens, prepare a fresh standard solution and make sure you are following the procedure correctly. Note that the standard solution must first be mixed with reagents and any reaction time must be observed as specified in the procedure.

What is the difference between Standard Adjust and User Calibration?

Standard Adjust multiplies the factory calibration curve by a factor that is based on the difference between a standard solution concentration and the displayed concentration. Typical limits for calibration curve adjustment are 10-20%. These limits ensure that if a standard solution were prepared incorrectly, the instrument would reject the adjustment.

User calibration puts an entirely new calibration curve into the instrument and does not have rejection limits if standards are prepared incorrectly. User calibration is not recommended for this reason, however local regulations may require you to do this.

I'm following the instructions for Adjusting the Standard Curve but the instrument will not accept the concentration I am entering. What is wrong?

Most likely the adjustment is outside the acceptable limits for the program you are using. Limits are programmed into the instrument to reject adjustments that are unreasonably far from the measured value. For example, if a 1.00 mg/L standard solution were placed in the instrument, and the displayed value were 0.77 mg/L, the instrument may not allow you to force it to read 1.00, because that would change the concentration by more than 20%.

Typical limits for standard adjustment are 10-20%, but can be more depending on the method. These limits ensure that if a standard solution were prepared incorrectly, the instrument would reject the adjustment.

If this happens, prepare a fresh standard solution and make sure you are following the procedure correctly. Note that the standard solution must first be mixed with reagents and any reaction time must be observed as specified in the procedure.

How can I find what wavelength a method uses on the DR/820, DR/850, or DR/890?

The following table lists the wavelengths used in the DR/890 Colorimeter instrument. The DR/890 Colorimeter uses four different wavelengths: 420, 520, 560, and 610 nm. Note the DR/820 uses only the 520 nm wavelength, and the DR/850 uses only 520 and 610 nm wavelengths.

Parameter Program Number Wavelength (nm)
Aluminum (Aluminon) 1 520
Aluminum User 610
Benzotriazole 3 420
Boron, LR 4 420
Bromine 5 520
Bromine (AV) 6 520
Cadmium User 560
Chloramine, Mono, LR 110 610
Chlorine, Free 9 520
Chlorine, Free (AV) 11 520
Chlorine, Free (TNT) 10 520
Chlorine, Free, HR 8 520
Chlorine, Free, HR+ 12 520
Chlorine, Total 9 520
Chlorine, Total (AV) 11 520
Chlorine, Total (TNT) 10 520
Chlorine, Total, HR 8 520
Chlorine, Total, HR+ 12 520
Chlorine Dioxide (DPD) 112 520
Chlorine Dioxide (DPD, AV) 113 520
Chlorine Dioxide, MR (Direct read) 7 420
Chromium, Hexavalent 13 560
Chromium, Hexavalent (AV) 14 560
Chromium, Total 15 560
Chromium User 520
COD, LR 16 420
COD, HR 17 610
COD, HR+ 17 610
COD, Mn III 18 520
Color, True and Apparent 19 420
Copper (Bicinchoninate) 20 560
Copper (Bicinchoninate, AV) 20 560
Copper (Porphyrin) 22 420
Copper User 420
Cyanide 23 610
Cyanide (Europe Only) User 560
Cyanuric Acid 24 520
DEHA 25 560
Fluoride 27 610
Fluoride (AV) 28 610
Hardness, Ca 29 520
Hardness, Mg 30 520
Hydrazine 31 420
Hydrazine (AV) 32 420
Iron, Ferrous 33 520
Iron, Ferrous (AV) 33 520
Iron, Total (FerroVer) 33 520
Iron, Total (FerroVer, AV) 33 520
Iron, Total (FerroMo) 38 610
Iron, Total (FerroZine) 37 560
Iron, Total (TPTZ) 39 610
Iron, Total (TPTZ, AV) 39 610
Iron User 520
Lead User 520
Manganese, LR 43 560
Manganese, HR 41 520
Molybdenum, HR 44 420
Molybdenum, HR (AV) 44 420
Molybdenum, LR 47 610
Nickel (PAN) 48 560
Nickel User 520
Nitrate, LR 55 520
Nitrate, MR 54 420
Nitrate, MR (AV) 53 420
Nitrate, HR 51 520
Nitrate, HR (AV) 50 520
Nitrate, HR (TNT) 57 420
Nitrite, LR 60 520
Nitrite, LR (AV) 62 520
Nitrite, LR (TNT) 63 520
Nitrite, HR 59 560
Nitrite (Europe Only) User 520
Nitrogen, Ammonia, LR 64 610
Nitrogen, Ammonia, LR (TNT) 66 610
Nitrogen, Ammonia, LR User 610
Nitrogen, Ammonia, HR (TNT) 67 610
Nitrogen, Ammonia, HR User 610
Nitrogen, Total, LR (TNT) 58 420
Nitrogen, Total HR (TNT) 69 420
Nitrogen, Total Inorganic (TNT) 68 610
Nitrogen, Total Kjeldahl 65 420
Oxygen, Dissolved, LR 71 610
Oxygen, Dissolved, HR 70 520
Ozone, LR 72 610
Ozone, MR 73 610
Ozone, HR 74 610
pH 75 520
Phosphonates 80 610
Phosphorus, Acid Hydrolyzable (TNT) 82 610
Phosphorus, Reactive (PhosVer3) 79 610
Phosphorus, Reactive (PhosVer3, AV) 79 610
Phosphorus, Reactive, LR (TNT) 82 610
Phosphorus, Reactive (Amino Acid) 85 520
Phosphorus, Reactive, HR 77 420
Phosphorus, Reactive, HR (AV) 78 420
Phosphorus, Reactive, HR (TNT) 86 420
Phosphorus, Reactive, LR User 610
Phosphorus, Reactive, HR User 610
Phosphorus, Total LR (TNT) 82 610
Phosphorus, Total HR (TNT) 87 420
Phosphorus, Total, LR User 610
Phosphorus, Total, HR User 610
Silica, LR 90 610
Silica, HR 89 420
Silica, UHR 88 420
Sulfate 91 520
Sulfate (AV) 92 520
Sulfate User 420
Sulfide 93 610
Surfactants 26 610
Suspended Solids 94 610
Tannin and Lignin 98 610
TOC, LR 116 610
TOC, MR 117 610
TOC, HR 115 610
ToxTrak 61 610
Turbidity 95 520
Volatile Acids 96 520
Zinc 97 610
Zinc (Europe Only) User 520

 

Flow Instrumentation

What is the difference between "Calibration" and "Level Adjust" on my flow meter?

Calibration is the user programmable span setting done before installation. Level adjust is intended to be used as a sensor offset during installation.

Can an Impeller Flow Sensor be used in an open channel?

No, Impeller Flow Sensors should only be used in closed pipe applications. The U53 UltraSonic Flow Meter using the UltraSonic Flow Sensor is designed for open channel applications.

Can an impeller flow sensor be used when the pipe/tee may not be full at all times?

No. The flow pipe must be full at all times when using an Impeller Flow Sensor. If the pipe is not full, the flow readings will be inaccurate.

Can I simulate a flow sensor signal when troubleshooting the F33, F53, or PRO-F3 Flow Analyzer?

The impeller flow sensor uses a 0 to 200 Hz frequency that can be simulated using the proper equipment. Contact the Process Technical Support Group for a general diagram.

 

HachLink Data Acquisition Software

I cannot download data from my instrument to my computer, what might be the problem?

The most common problem with downloading data is the RS232 cable. If the cable was not purchased from Hach for your instrument, try using a null-modem adapter with your cable. The null-modem adapter often (but not always) corrects the problem.

To avoid problems with data transfer, be sure to get the Hach RS232 cable that is designed for use with your instrument. If you are using a cable from Hach, make sure the selected port in HachLink is the same port that the cable is physically connected to on your computer.

If using a DR/4000 spectrophotometer, make sure that output is turned on in the setup menu: setup-->Serial I/O-->output: ON.

The data from my DR/4000 spectrophotometer appears in the HachLink2000 table but nothing appears in the graph window. How can I get it to show the graph?

When setting up the port in HachLink, on the tabular tab, first select the program and then also make sure the group is set to match the group displayed on the DR/4000 for that program.

 

Incubators

How long will the batteries for the portable incubator (Catalog No. 25699-00) last?

A charged battery for the portable incubator will last 12 hours at ambient temperature. Because microbiological tests normally require at least 24 hours incubation, the portable incubator is best used for transport of samples to a place where the incubator can be plugged into an electrical outlet using the battery eliminator. The portable incubator can also be plugged into the cigarette lighter of an automobile.

At minimum take 3 charged batteries with you into the field. The total number of batteries needed depends on the incubation time for your test, the temperature at the location where the incubator will be used, and the availability of an electrical outlet or automobile. The batteries can be recharged using the battery recharger, which must be plugged into an electrical outlet.

 

InSight Data Acquisition Software

InSight gives me an error message when I try to connect to my Sigma Sampler or Flow Meter via the RS232 serial port.

If you are using the DOS version of InSight, try shutting Windows down and restarting the computer in DOS mode. Run InSight from the DOS prompt and try again. This will typically only work on Windows 95 and 98 systems. If running Windows 2000 or XP you must upgrade to the latest version for compatibility.

Also check the following: Make sure you are using a genuine Sigma PN1727 cable which has yellow shrink tubing on the meter end. Make sure the baud rate set in the sampler or flow meter matches the baud rate set in InSight. Check the COM port to be sure the physical connection matches what is shown in InSight. Or try one of the other COM ports by changing the choice in InSight; if COM 1 doesn't connect, try COM 2, and etc.

 

pH Meters and Electrodes

How often do I need to dispense the gel in my Platinum Series electrode?

Click the dispenser two or three times every day before calibration. You can then measure several samples without clicking the dispenser, unless you rinse the electrode very vigorously between samples. Click the dispenser every five to ten samples after calibration.

My pH reading is unstable and erratic. I´m using a Platinum Series Electrode. What can I do?

Most likely the electrolyte gel in the Platinum Series Electrode is not making contact with the sample or buffer, or there is an air bubble in the gel.

Click the dispenser on the electrode until the electrolyte gel comes out and the pH reading is stable. See the electrode instruction manual for more information on the electrolyte gel cartridge.

How long can I expect my pH electrode to last?

pH electrodes typically last from 6 months to 2 years before needing replacement depending on the type of electrode (I.e. gel vs. refillable). The glass bulb of a pH electrode has an electrical resistance that naturally changes over time. When this resistance gets too high, the electrode may not function properly and the meter will not accept calibrations or measurements .

How often do I need to calibrate my pH meter?

Your pH meter should be calibrated every day or prior to use for most accurate pH results. If continuously used in the process, it is suggested to calibrate at least once per eight-hour shift.

What should I store my pH probe in when I´m not using it?

Storage of a pH electrode can affect the life of the electrode and how quickly it responds or stabilizes in different types of samples. Since the internal and external components are separated by a reference junction, a phenomenon called osmosis can occur if different molarity solutions are in contact with each other for too long, causing a drift in the internal reference. To prevent this from occurring, store the electrode in the Hach Electrode Storage Solution or a 3 M potassium chloride (KCl) solution for Hach pH electrodes. The electrode can be stored for up to 2 hours in sample (if sample pH is not extreme) or in a neutral solution such as tap water between uses to prevent drying of the reference junction, but remember the greater the difference in molarity between the sample and internal solution of the electrode, the more problems that can occur. Do not leave the electrode in deionized or distilled water for more than 15 - 30 minutes. The electrolyte or internal filling solution can become diluted due to osmosis and adversely affect the function of the electrode.

If the electrode has become dehydrated, let the probe soak in the 4, 7 and 10 buffers for 5 minutes each and repeat 2x. Then soak the electrode tip in a 3.0 M KCl storage solution for 1-2 hours and rinse with deionized water prior to use.

How should I clean my pH electrode?

Cleaning an electrode may improve performance when the response and stabilization time become noticeably slower. For a mild cleaning, place the probe in a detergent solution such as Alconox for thirty minutes, and then soak in deionized water for approximately 15 minutes before use.

For a more vigorous cleaning, place the probe in 0.1 N HCl solution for two minutes, rinse with deionized water, place in a 0.1 N NaOH solution for two minutes, then rinse and place in the HCl solution again for two more minutes. Rinse the probe and allow to soak in deionized water for approximately 15 minutes.

To clean organic build up on the probe, place the probe in liquid bleach for five minutes, then soak in deionized water for 15 minutes.

What buffers do I need for pH calibration?

Two buffers should be used for calibration of a pH meter or tester. If the expected pH of the sample is below 7, use pH 4 and 7 buffers. If the expected pH is above 7, use pH 7 and 10 buffers.

pH buffers come in either powder pillows or as solutions. Powder pillows have a longer shelf life and are more economical than solutions but are less convenient. Buffer solutions are very convenient but can be prone to contamination if left open.

Buffer solutions can be poured from the bottle into a small beaker, or if using Singlet Solution Packs, the electrode can be placed directly in the solution bag. Buffer powder pillows require preparation by mixing with 50-mL deionized water before each calibration.

Once used for calibration, buffer solutions should be discarded. Buffer solutions in bottles should always be poured into a beaker for calibration, and used buffer should never be poured back into the bottle.

How much deionized water needs to be mixed with a pH buffer powder pillow?

Add 50 mL of deionized or distilled water to a small beaker and add the contents of one buffer powder pillow. Mix thoroughly until all powder is dissolved. Discard the solution after calibration.

My sensION pH meter shows 7.00 and won´t change when trying to calibrate or measure. It also shows error 2 or 3 when I´m trying to calibrate. What can I do?

This can happen when using an electrode with a 5-pin connector. Press the Setup key and be sure the display shows 5-pin and not BNC. If the display shows BNC, press the Enter key to change it to 5-pin. The meter will accept electrodes with either the 5-pin or BNC connector, but you must select which one is being used in the Setup mode.

If 5-pin is selected in the Setup mode and the pH values still don´t change in a different buffer, the glass bulb of the electrode is likely cracked or damaged and the entire electrode must be replaced.

What is a pH calibration slope, and what value should it be?

The calibration slope is a conversion that the pH meter uses to convert the electrode signal in mV to pH. The meter determines the slope by measuring the difference in the mV reading of two different buffers and divides it by the difference in pH of the buffers.

For example, if the electrode reads 2 mV in the 7 buffer, and 182 mV in the 4 buffer, the slope is (2-182)/(7-4) or -60 mV per pH unit. The slope should be -58 (+/- 3) mV per pH unit, or any value between -55 and -61 mV.

What should I do if my pH meter won't calibrate?

If instructions are closely followed but the meter will not accept the calibration, most likely the problem is with the electrode. You can check whether the electrode is still good by measuring the mV reading of the electrode in the pH buffers.

Place the electrode in a pH 7 buffer solution and press the mV key to show the mV reading. The meter should read between -30 and 30 mV. The mV reading in the pH 7 buffer is called the offset. If the offset is outside of this range, try cleaning the electrode, and replace the gel cartridge or filling solution. Also make sure you are using a fresh buffer solution. If the mV reading is still outside of this range, the electrode needs to be replaced.

If the mV reading is within this range, check the reading of the electrode in the pH 4 or 10 buffer. The reading in the 4 buffer should increase by 174 (+/- 9) mV or anywhere from 165-183 mV, and the reading in the 10 buffer should decrease by 174 (+/- 9) mV.

For example, if the reading in the pH 7 buffer is 2 mV and the reading in the pH 10 buffer is -180 mV, the reading decreased by 182 mV, which is within the specified range. If the difference in mV between the pH 7 and or 10 buffer is outside of the specified range, try cleaning the electrode, and replace the gel cartridge or filling solution. Also make sure you are using fresh buffer solutions. If the mV reading is still outside of this range, the electrode needs to be replaced.

If the offset of the electrode and the difference between the offset and mV reading in a pH 4 or 7 buffer is within the specified range, the calibration problem is not due to the electrode. Carefully review the calibration procedure to be sure that the instructions are being followed exactly.

How can I tell if my sensION meter needs repair?

Problems with pH measurement are usually due to a problem with the electrode, however it may be worthwhile to check the meter to be sure it is operating correctly.

This can be done by shorting out the 5-pin or BNC electrode connection on the meter and checking to see that the reading in the mV mode is 0.0 (+/- 0.1) mV.

To short out the BNC connection, screw on the BNC shorting cap. Go into the setup mode and make sure the display says BNC, then press the mV key.

To short out the 5-pin connector, use a wire or a paper clip and make sure 5-pin is selected in the setup mode. Looking at the 5-pin connector on the back of the instrument, place one end of the paper clip in the 11 o´clock pin hole and the other end against the outside ring (not the half circle) of the connector.

If the reading is not within the -0.1 to 0.1 mV range, press the Cal and Enter keys simultaneously while the connector is shorted. If the mV reading is still outside of the specified range, the meter should be sent in for service.

 

pH/ORP On-line Analyzers

Why can´t ORP reference solutions be used for calibrating pH Analyzers and visa-versa?

ORP reference solutions and pH buffers are designed specifically for either pH or ORP, but are not interchangeable. ORP sensors use the oxidation-reduction potential of ORP reference solutions, whereas pH sensors use the hydrogen ion concentration of pH buffer solutions.

How often does the salt bridge and standard cell solution on a five-wire differential pH or ORP sensor have to be changed?

We recommend changing the salt bridge and standard cell solution one to two times a year. This prevents the standard cell from becoming contaminated, which can cause an offset in the process signal and increased sensor calibrations.

What is the expected life of a pH/ORP differential sensor?

This is a difficult question to answer since sensor life depends on the process characteristics and how well it is maintained: The pro-rated replacement pricing extends to 30 months or 2.5 years. This is a good barometer of sensor performance.

Why isn´t a pH 10 buffer solution recommended for calibrating my pH Analyzer?

A pH 10 buffer solution is unstable and deteriorates rather quickly because it absorbs carbon dioxide (CO2) from the air. When CO2 is absorbed in water, it forms carbonic acid, which lowers the pH of the buffer.

To prevent potential problems from calibrating with innacurate pH 10 buffer solutions, we recommend calibrating with pH 4 and 7 buffers. This establishes a slope value which carries over to the high pH side. You can use the 10 pH buffer to calibrate, but need to be aware of the potential variables.

What is the difference between the GLI 2-wire and 5-wire pH/ORP sensors?

The GLI 2-wire sensors have uncalibrated 4-20 mA loop powered transmitters. These sensors were used with GLI model 670 and 95G analyzers which are no longer available. The 2-wire sensors can be directly connected to a controlling device, but require the user to generate a program that allows for sensor calibration.

The 5-wire differential sensors are used with an analyzer that provides voltage to power the internal preamp and a differential input section. The two sensor types are not interchangeable.

What solution is used in the standard cell?

GLI uses a special pH 7 solution containing stabilizers and mold inhibitors to prevent contamination. In addition, this solution is at least 10 times more resistant to changes in pH than the pH 7 calibration buffer.

What will happen if I try to calibrate my pH Analyzer when the sensor and calibration buffers are at different temperatures?

If the sensor and calibration buffers are not at temperature equilibruim, the calibration will have an offset when the sensor is installed back in the process. The GLI microprocessor-based analyzers may not accept the calibration if it detects drift in the temperature reading.

The display on the P63 pH Analyzer remains at 7pH no matter what solution the pH probe is placed in.

This is likely due to a problem with the wiring or with the calibration.

If the pH probe is wired into a junction box, then attached to the analyzer using an interconect cable, disconnect the probe from the junction box and connect it directly to the analyzer. If the problem is corrected, check the junction box for corrosion, incorrect wiring, or poor connections.

If the pH probe is connected directly to the analyzer and the problem remains, check the calibration as follows:

  1. Push the "Diag" button on the display unit.
  2. Choose CALIBRATION RECORD and press "Enter".
  3. Check the buffer values shown for the last calibration.
  4. If the buffer values are incorrect, recalibrate the probe. Choose Yes when asked IS THIS PROBE BEING CALIBRATED FOR THE FIRST TIME? Make sure that the displayed pH buffer value matches the value that the probe is placed in.

 

Pocket II Colorimeters

I just received a Pocket Colorimeter II for pH and Chlorine (Catalog No. 5870012). The procedure says to use 5-mL of sample but I received DPD reagent for 25-mL of sample. Is this a mistake?

The procedure is correct. Add 5 mL sample to the plastic 1-cm/10-mL sample cell, and add the DPD reagent for 25-mL of sample.

The DPD reagent was originally formulated to measure a lower range of chlorine. The ratio of 25-mL DPD reagent to 5-mL sample allows the range on this instrument to extend to 10.0 mg/L Cl2.The reagent inside a 5-mL and a 25-mL DPD powder pillow differs only in the amount (weight fill) of reagent inside the pillow.

Is the Catalog Number for the Immunoassay Adapter the same for the Pocket II Colorimeter as for the older model Pocket Colorimeter?

The adapter that fits in the sample cell compartment is different for each instrument. Use Catalog No. 5954600 for the adapter used in Pocket II Colorimeters, and Catalog No. 4879800 for the adapter used in the older model Pocket Colorimeters. This adapter is included with kits for immunoassay methods such as TPH, PCB, Atrazine, Metolachlor, and Alachlor. Additional adapters are not necessary unless the one that came with your kit is lost or damaged.

My Pocket II Colorimeter turns off by itself. Is this normal?

Yes, the instrument will automatically turn off if not used for 15 minutes. This feature conserves battery usage. If entering a calibration in the User-Entered Calibration mode, the automatic shut-off is 60 minutes to allow time for standard preparation and measurement.

I get very different readings for chlorine when I put the same sample cell in the Pocket II Colorimeter for chlorine vs. the pocket colorimeter for pH and chlorine. Why is this?

The glass and plastic sample cells that come with each colorimeter are not interchangeable. The glass sample cells that come with the Chlorine Pocket II Colorimeter (Catalog No. 5870000) cannot be placed in the Chlorine & pH Pocket II Colorimeter (Catalog No. 5870012) to compare results.

When using the low range (0 - 2.00 mg/L Cl2) of the chlorine colorimeter, you must use the glass cells. To compare results to the pH & chlorine coloirmeter, transfer both the blank and reacted sample to the plastic sample cells. Results between the two instruments should be similar when the correct sample cells are used.

If you are using the high range (0 - 8.0 mg/L Cl2) of the chlorine colorimeter, you must use the plastic sample cells. In this case you can place the same sample cells directly into the pH & chlorine colorimeter. Results between the two instruments should be similar.

The glass sample cells that come with the Chlorine & pH colorimeter can only be used for measuring pH.

How do I dilute the primary Chlorine Standard Solution (Catalog No. 1426810 or 1426820) to prepare calibration standards for calibrating my Pocket II Colorimeter for Chlorine (Catalog No. 5870000)?

If you are required to calibrate your Pocket II Colorimeter, you will need to prepare several (typically 5 to 7) primary calibration standards at different concentrations. The calibration standards should span the full concentration range of the test you use. For example, if you use a Hach method that measures from 0 - 2.00 mg/L, prepare calibration standard concentrations that span this range, for example 0.3, 0.6, 0.9, 1.2, 1.6, and 1.9 mg/L Cl2.

The following procedure is one way to accurately prepare 6 chlorine calibration standards from a Hach Chlorine Standard Solution.

Required Items:

  • Chlorine Standard Solution, 50-75 mg/L (actual concentration on label): Catalog No. 1426810
  • Flasks, volumetric, class A, glass, 200-mL: Catalog No. 1457445
  • Pipets, volumetric, class A, glass, 1, 2, 3, 4, 5, and 6 mL: Catalog No. 1451535, 1451536, 1451503, 1451504, 1451537, 1451506
  • Pipet Filler: Catalog No. 1218900
  • Deionized water: Catalog No. 27256

Diluting the Chlorine Standard Solution:

  1. Fill a 200-mL volumetric flask approximately half full with deionized water.
  2. Open a chlorine standard solution ampule.
  3. Pipet 1 mL of the chlorine standard solution into the flask.
  4. Fill the flask to the mark with deionized water, stopper, and invert repeatedly to mix. This makes an approximately 0.3 mg/L Cl2 standard solution. (Use the equation below to find the exact concentration.)
  5. Prepare additional standards by repeating the above steps, substituting 2, 3, 4, 5, and 6 mL of the chlorine standard solution for the 1 mL shown in step 3.

Calculating the Concentration:

Because Chlorine Standard Solutions are difficult to prepare accurately, Hach targets a concentration range, in this case 50 to 75 mg/L, and then determines the actual concentration by amperometric titration. You will find the actual concentration on the label. Use this concentration to calculate each of your calibration standard concentrations.

Multiply the concentration from the Chlorine Standard Solution label by the multipliers in the following table.

Standard # Pipet volume (mL) Multiplier
1 1 0.005
2 2 0.01
3 3 0.015
4 4 0.02
5 5 0.025
6 6 0.03

Diluted concentration = chlorine ampule concentration x multiplier

Example: Your chlorine standard solution (Catalog 1426810) is 63.1 mg/L. You pipetted one mL of this standard into a 200-mL flask and diluted to the mark. The concentration of your diluted standard is 63.1 x 0.005 = 0.32 mg/L chlorine. Enter 0.32 in the calibration mode of your Pocket II Colorimeter for standard 1. Measure the absorbance of this standard after adding the DPD reagent.

Note: Use the diluted standard solutions as soon as possible after mixing.

How can I correct my Chlorine DPD test for interference from oxidized manganese or chromium?

Pretreat your sample with potassium iodide and sodium arsenite as described below. This pretreatment destroys any chlorine in the sample, and allows you to measure and subtract the concentration due only to the manganese or chromium interference.

  1. Adjust at least 25 mL of sample to pH 6-7 using 1 N sulfuric acid or 1 N sodium hydroxide.
  2. Add 3 drops potassium iodide, 30 g/L (Cat. No. 343-32) to 25-mL of the pH-adjusted sample.
  3. Mix and wait one minute.
  4. Add 3 drops sodium arsenite, 5 g/L (Cat. No. 1047-32) and mix. The arsenite destroys any chlorine in the sample but not manganese or chromium.
  5. Pour 10 mL (or the required amount for your instrument or test kit) of the treated sample into a sample cell and add the DPD reagent. Wait 3 minutes if using total DPD reagent. Read the concentration in your instrument or kit.
  6. Subtract this concentration from your original result (without the pretreatment) to find the correct chlorine concentration.

How do I store data with the Pocket Colorimeter II?

The 10 most recent data points are stored automatically on a first in, first out basis, and can be recalled at a later time. Data cannot be downloaded to a computer; it must be recalled manually.

To recall data, press the MENU key, then press the ZERO/SCROLL key until the display shows RCL. Then press the READ/ENTER key to view the stored measurements.

What is the lowest level I can measure with the Pocket Colorimeter II?

Detection limits for each parameter can be found in the Method Performance section of the instrument manual. The detection limits are determined using the concentration at 0.010 absorbance.

The display on my Pocket II Colorimeter flashes 0, 0.0, or 0.00 when I try to measure a sample. What does this mean?

Most likely the concentration in your sample is zero, or below the detection limit of the instrument. Use a lower range method if one is available. At very low concentrations, any optical differences in the sample cells become significant. Try using one sample cell for both zeroing the instrument and reading the sample to minimize these optical differences.

If you are using SpecCheck Standards, be sure to zero the instrument with the blank vial that comes in the SpecCheck set and not with water. If you are testing a parameter where the blank is darker than the sample, such as fluoride or ozone, be sure you are zeroing the instrument with the darker blank and reading the lighter sample.

Some SpecCheck Standards, such as for fluoride and ozone, require zeroing with one of the standard vials and reading the clear blank. This is opposite from how samples are measured, but in each case the instrument is zeroed with a dark color, and the lighter color is then read.

The display on my Pocket II Colorimeter shows a flashing square. What does this mean?

The flashing square indicates that the instrument needs to be zeroed before it can take a measurement. Place a sample cell containing your blank solution into the instrument and press the zero key.

Is there a very small carrying case for the Pocket Colorimeter II?

The Pocket Colorimeter II Holster, Catalog No. 5953100, is a carrying case made from durable fabric. Place your instrument, sample vials, and reagents in the holster. Then place the holster on your belt for convenience when taking field measurements.

When I test the sample in my Pocket II Colorimeter using the high range I get one reading, and then I test the same sample on the low range and get a totally different reading. Why?

The procedure is different for the 2 ranges; make sure you are following the correct procedure for the range you are using. The high range uses more reagent than the low range. The high range also uses a plastic sample cell instead of the glass cell used for the low range.

The manual for my Pocket Colorimeter II includes several parameters; can I measure all of these parameters with this instrument?

The instruction manual may include other parameters that can be measured at the same wavelength as your instrument, however each Pocket Colorimeter II is calibrated to measure only one parameter.

It may be possible to add a user calibration to measure one other parameter using reagents for that parameter, however it requires that the additional parameter be one of the ones in the same procedure manual, and that the range not exceed that for which the instrument is calibrated. The instrument will overrange at the upper limit given for that particular instrument. For instance, if the instrument overranges at 3.30 mg/L, a user calibration will also overrange at 3.30 mg/L.

I received both glass and plastic sample cells with my Pocket Colorimeter II. Which should I use?

The different sample cells correspond to different concentration ranges in the instrument. Many Pocket Colorimeters have a low and high range. For example, the Pocket Colorimeter II for Chlorine (Catalog No. 5870000) measures chlorine in a low range mode from 0.02 - 2.00 mg/L Cl2, and in a high range mode from 0.1 - 8.0 mg/L Cl2. The step-by-step procedure is different for the low vs. high range.

Glass sample cells should be used when measuring in the low range mode, and plastic cells should be used when measuring in the high range mode. If using the Pocket Colorimeter II for pH and Chlorine, use the glass sample cells when measuring pH and the plastic cells when measuring chlorine.

The plastic cells have a shorter pathlength, and the calibration is different when glass vs. plastic cells are used. If a glass cell is used for a range that is calibrated with a plastic sample cell, the readings will be erroneously high.

Note that the plastic cell used with older model Pocket Colorimeters will not fit correctly in the Pocket Colorimeter II. Use Catalog No. 4864302 with the Pocket Colorimeter II and 4165802 with older (blue) Pocket Colorimeters.

My SpecCheck standard #3 reads slightly high on the Pocket Colorimeter II, and falls outside of the range on the Certificate of Analysis. Why is this?

You likely have an older lot of the SpecCheck standards. Newer lots have an expanded range on the Certificate of Analysis to account for different readings on the Pocket Colorimeter II vs. older model Pocket Colorimeter.

The reason for the different readings is somewhat complicated, but has to do with the fact that the two instrument models have different optics, and the absorption spectra of SpecCheck standards vs. samples prepared with DPD is different. For instance, a wavelength vs. absorbance spectrum for the pink DPD compound in samples is different from the spectrum of the DPD SpecCheck standards.

The Pocket Colorimeter II will see these spectra differently than the older model Pocket Colorimeter, therefore the two instruments will display slightly different results. These differences do not indicate that there is anything wrong with the instrument. The most important thing is to record the value that the SpecChecks read when the instrument is new, and see if this value changes over time. If the value does not change significantly, you can be confident that the instrument response has not changed.

My Pocket II Colorimeter reads much higher than it should using the SpecCheck standards. Does my instrument need repair?

Be sure your Pocket II Colorimeter shows "LR" on the display when measuring SpecCheck standards. The values shown on the SpecCheck Certificate of Analysis are determined for the "LR" mode only.

You can use the SpecCheck standards with the "HR" mode on your instrument, but you cannot compare results to the values on the Certificate of Analysis. To use SpecCheck standards with the "HR" mode on your instrument, record the results in the "HR" mode when you first get the standards. Compare future readings to these results.

If future results do not differ from your recorded results by more than 5%, you can be confident that your instrument response has not changed. If the results change by more than 5%, there may be a problem with your instrument.

What is the difference between standard adjust and user calibration on the Pocket Colorimeter II?

Standard adjust maintains the shape of the factory calibration curve, but the whole curve is adjusted slightly so that the instrument reads the exact value of a standard solution. Typical limits for calibration curve adjustment are 10-20 percent. These limits ensure that if a standard were prepared incorrectly, the instrument would reject the adjustment.

User calibration puts an entirely new calibration curve into the instrument, and does not have rejection limits if standards are prepared incorrectly. User calibration is not recommended for this reason, however it may be required by regulations.

 

Pocket Colorimeters

I get very different readings for chlorine when I put the same sample cell in the Pocket Colorimeter for chlorine vs. the pocket colorimeter for pH and chlorine. Why is this?

You should be able to get similar results in the two instruments only when comparing the high range of the chlorine colorimeter to the pH and chlorine colorimeter using the plastic sample cells.

If you are comparing results to the low range of the chlorine colorimeter, you cannot use the plastic sample cell for comparison between the instruments. The low range is calibrated using the glass sample cell, which has a larger diameter than the plastic cell.

Note: older models of the pH and chlorine pocket colorimeter required diluting the sample from 10 to 25 mL with deionized water for every chlorine sample. If the deionized water is not added, the colorimeter will read approximately 2.5 times too high.

When I test the sample in my Pocket Colorimeter using the high range I get one reading, and then I test the same sample on the low range and get a totally different reading. Why?

The procedure is different for the 2 ranges; make sure you are following the correct procedure for the range you are using. The high range usually uses more reagent than the low range and also uses a different sample cell having a shorter pathlength.

My Pocket Colorimeter displays E2 when I press the read key, what does this mean?

An E2 error message on the pocket colorimeter indicates that the unit should be sent in for repair. It is typically related to a bad interference filter. Excess moisture can increase the failure of these filters.

The display on my Pocket Colorimeter flashes 0, 0.0, or 0.00 when I try to measure a sample. What does this mean?

Most likely the concentration in your sample is zero, or below the detection limit of the instrument. Use a lower range method if one is available. At very low concentrations, any optical differences in the sample cells become significant. Try using one sample cell for both zeroing the instrument and reading the sample to minimize these optical differences.

If you are using SpecCheck Standards, be sure to zero the instrument with the blank vial that comes in the SpecCheck set and not with water. If you are testing a parameter where the blank is darker than the sample, such as fluoride or ozone, be sure you are zeroing the instrument with the darker blank and reading the lighter sample.

Some SpecCheck Standards, such as for fluoride and ozone, require zeroing with one of the standard vials and reading the clear blank. This is opposite from how samples are measured, but in each case the instrument is zeroed with a dark color, and the lighter color is then read.

My Pocket Colorimeter reads much higher than it should using the SpecCheck standards. Does my instrument need repair?

Be sure you are using the "LO" mode on the Pocket Colorimeter when measuring SpecCheck standards. The values shown on the SpecCheck Certificate of Analysis are determined for the "LO" mode only.

You can use the SpecCheck standards with the "HI" mode on your instrument, but you cannot compare results to the values on the Certificate of Analysis. To use SpecCheck standards with the "HI" mode on your instrument, record the results in the "HI" mode when you first get the standards. Compare future readings to these results.

If future results do not differ from your recorded results by more than 5%, you can be confident that your instrument response has not changed. If the results change by more than 5%, there may be a problem with your instrument.

 

Sampler

My Sampler blew a 5 AMP fuse, what could have caused it?

The 5-Amp fuse protects the pump motor from damage in the event that a hard object in the pump housing or tubing jams the rollers. First, disconnect all power from the sampler. Next, remove the pump cover and tubing. Clean the rollers of all debris.

Check the tubing and replace if worn or leaking. The pump tubing must be positioned properly in the pump. The dots on the tubing should line up with the edge of the tubing entrance and exit points on the pump body (see the O&M manual for details on proper tubing installation). Do not stretch the tubing during installation. Reinstall the pump cover. Always replace the fuse with the exact same rating as the original.

 

Series 5000 On-line Analyzers

How do I access the troubleshooting function on a Series 5000 analyzer?

Remove the plastic cover on the control unit. On the microprocessor board, set the first SW1 dip switch to the ON (closed) position.

I replaced the reagents in my Series 5000 analyzer, and the reagents were completely consumed after a few days. Why did this happen?

This can happen after changing the tubing in the instrument and failing to put the reagent tubing module back into the analyzer. Place the reagent tubing module back in the instrument and replace the reagents.

Series 5000 Silica Analyzer has been out of service and now will not calbrate.

If the unit was not drained and cleaned before being taken out of service, the system should be thoroughly cleaned:

  • flush the tubing with deionized water
  • clean the sample cell
  • install fresh reagents
  • prime the reagents
  • with the instrument on, lift the cell cover and make sure each reagent is being dispensed into the sample cell

My Series 5000 Silica Analyzer fails the calibration, what can I do?

The Series 5000 Analyzer will fail to calibrate if one of the solenoid valves is leaking. Follow these steps to find a leaking solenoid valve:

  1. Remove the sample cell cover
  2. Turn the instrument power off, but leave the instrument air on
  3. On the sample cell cover, dry the straws with a paper towel, and inspect the straws for cracks
  4. Place the cell cover on a clean, dry paper towel and let it sit for 20 minutes.
  5. After 20 minutes, examine the straws for moisture. If one of the straws has moisture on it, trace the line back to the solenoid valve
  6. Replace the solenoid valve

What should I do when shutting my on-line analyzer down for an extended period of time?

When shutting an on-line analyzer down for an extended period of time, it is important that reagents be flushed from the system to prevent future start-up problems. Be sure to:

  • Remove reagents
  • Flush tubing with deionized water
  • Remove the pinch plate if your analyzer has one

A blue gooey substance keeps forming in my Series 5000 Silica Analyzer. I've cleaned it out but it keeps coming back. What can I do?

The cause of this substance is not known. Cleaning the substance out of the sample cell, tubing, etc. removes it only temporarily.

To keep this substance from forming, it is necessary to replace the sample cell, sample cell cover, and all of the tubing and fittings.

 

SP510 Hardness Analyzer

I need replacement standards to calibrate my SP510 Hardness Analyzer and they are not listed in the manual. What are the part numbers?

The 10 g/L EDTA solution (for the SOFT CAL) is Catalog No. 102133. The 10 g/L Magnesium Standard Solution (for the HARD CAL) is Catalog No. 102233.

 

Test Strips

Which end of the Test Strip do I match to the bottle?

For Test Strips that have more than one pad, orient the strip as indicated on the bottle using the picture of the thumb.

Do Hach Test Strips expire?

Yes, the expiration date is printed on the bottle. Be sure to replace the cap on the bottle right after use and store in a cool place. This is the best way to be sure that Test Strips will last until the expiration date.

My Test Strips have color before they are even used. Does this mean they are bad?

No, the pad on Test Strips for many tests such as hardness have color before use. This is normal and does not indicate a quality problem.

What is the accuracy of Hach Test Strips?

Hach Test Strips are semi-quantitative and are accurate to +/- one half of a color block. Quantab strips are accurate to +/- 10 percent.

How can I extend the range of the Quantab Test Strips for chloride? The number on my strip is above (or below) the numbers shown on the bottle.

The range for these strips cannot be extended above or below the limits shown on the bottle. The calibration is not linear and results will not be accurate outside of the stated range.

Samples above the range can be diluted until the chloride concentration is in the measurable range. Results for diluted samples should be multiplied by the dilution factor. To measure samples below the lower limit on the strips, a different method such as titration should be used.

How do the Quantab test strips for chloride work?

When the Quantab® strip is placed in aqueous solutions, fluid rises up the strip by capillary action. When the strip is completely saturated, a moisture sensitive string across the top of the titrator turns dark blue.

The strip contains silver ions, which combine with chloride in the sample to form a white column of silver chloride. The length of the white column (silver chloride) in the strip is proportional to the chloride ion concentration.

Each lot of Quantab strips is calibrated independently, so that the chart on the bottle where you find the chloride concentration may differ from a previous bottle.

Why do the Quantab Test Strips have a scale that goes to 10, but the numbers on the bottle don't go up that high?

Each lot of Quantab Test Strips for chloride is calibrated independently, therefore the highest chloride concentration for one lot may correspond to a different number on the strip for a different lot.

Although most lots are not calibrated to go up to the top of the scale, the 0-10 scale on the strip can be divided into increments of 0.2, which is easy to read.

What can interfere with the Quantab Test Strips for chloride?

The Quantab Test Strip reaction involves the formation of silver chloride on the strip from the combination of silver on the strip with chloride in the sample. Any anion (for example bromide, iodide, cyanide, and sulfide) which will react with the silver to give an insoluble precipitate may interfere with the Quantab® test and give a higher than actual result.

Strong acids may also interfere, however the strips will work in caustic or extremely high pH samples. Nitrite and nitrate have no adverse effect on the Quantab® test.

Quantabs will work in colored solutions as long as they are clear, however turbid solutions can clog the wick and cause very slow or incomplete reactions. Filter turbid samples before testing.

Quantab strips can be used in a wide range of temperatures.

 

DR 5000

How do I read lower than 15 Color Units with the DR 5000 spectrophotometer?

The DR 5000 spectrophotometer can read color below 15 Color Units, but one must determine the Method Detection Limit as shown in the Water Analysis Handbook to find the lowest value. Additionally, the use of sample cells with longer pathlengths (i.e. 5 cm or greater) will enable you to effectively read solutions with low levels of color.

 

9185sc Ozone Sensor

Were the problems with temperature compensation corrected in the new sc instruments?

Yes, the probe was inserted deeper into the sample to eliminate the effects of sample/ambient temperature fluctuations.

Has the pH compensation for the TFC unit improved?

Yes, the pH sensor has been upgraded to a gel filled zerolyte combination electrode. This electrode is a better device than the previous 9184 used.

Do I need a constant head device for these instruments?

No, the flow cell has built in flow control. Merely set the water level in the left chamber to just exit out the overflow. This will provide a constant 14L/hr flow rate to the sensor.

Do I need to purchase any additional item to complete my installation?

The only customer supplied items are the influent tubing, mounting hardware to attach the pre-assembled mounting panel to an appropriate surface, and sample water. Effluent tubing is provided.

Can my existing 9184 be converted to the new style that works with the sc100/sc200/sc1000?

No. Due to changes that were made to improve the systems operation, temperature, and pH a complete new system needs to be purchased.

Can I purchase the 9184sc HOCl sensor and then upgrade to the TFC version at a later time?

Yes. You would need to purchase the pH sensor (368416,00000) and pH cable (09184=A=4400).

Is there a different gateway for each of the 9180sc sensors?

No, the gateway is the same for all the 9180sc Digital Amperometric Sensors.

Is the sc100/sc200 mounting panel the same as the sun shield?

No, the mounting panel is to provide a common mounting size and look for this product offering. The sun shield is designed for applications where the sc100/sc200 needs to be shielded from direct sunlight and would need to be purchased separately. The sc100/sc200 mounting panel is available for individual sale.

When do I use the acidification unit?

The 9180sc Acidification Unit should be used to adjust the influent pH of the sample for chlorine measurement when the pH is greater than 8. The 9180sc Acidification Unit can be used for continuous or intermittent cleaning of the flow cell for any of the 9180sc sensors.

Why would I use the intermittent flow unit?

The 9180sc Intermittent Flow Unit is used to eliminate constant measurement while saving resources. An example of this might be at a remote pumping station where measurements are needed only once per hour. In this case, the amount of water expelled to drain is reduced.

 

9187sc Chlorine Dioxide Sensor

Were the problems with temperature compensation corrected in the new sc instruments?

Yes, the probe was inserted deeper into the sample to eliminate the effects of sample/ambient temperature fluctuations.

Has the pH compensation for the TFC unit improved?

Yes, the pH sensor has been upgraded to a gel filled zerolyte combination electrode. This electrode is a better device than the previous 9184 used.

Do I need a constant head device for these instruments?

No, the flow cell has built in flow control. Merely set the water level in the left chamber to just exit out the overflow. This will provide a constant 14L/hr flow rate to the sensor.

Do I need to purchase any additional item to complete my installation?

The only customer supplied items are the influent tubing, mounting hardware to attach the pre-assembled mounting panel to an appropriate surface, and sample water. Effluent tubing is provided.

Can my existing 9184 be converted to the new style that works with the sc100/sc200/sc1000?

No. Due to changes that were made to improve the systems operation, temperature, and pH a complete new system needs to be purchased.

Can I purchase the 9184sc HOCl sensor and then upgrade to the TFC version at a later time?

Yes. You would need to purchase the pH sensor (368416,00000) and pH cable (09184=A=4400).

Is there a different gateway for each of the 9180sc sensors?

No, the gateway is the same for all the 9180sc Digital Amperometric Sensors.

Is the sc100/sc200 mounting panel the same as the sun shield?

No, the mounting panel is to provide a common mounting size and look for this product offering. The sun shield is designed for applications where the sc100/sc200 needs to be shielded from direct sunlight and would need to be purchased separately. The sc100/sc200 mounting panel is available for individual sale.

When do I use the acidification unit?

The 9180sc Acidification Unit should be used to adjust the influent pH of the sample for chlorine measurement when the pH is greater than 8. The 9180sc Acidification Unit can be used for continuous or intermittent cleaning of the flow cell for any of the 9180sc sensors.

Why would I use the intermittent flow unit?

The 9180sc Intermittent Flow Unit is used to eliminate constant measurement while saving resources. An example of this might be at a remote pumping station where measurements are needed only once per hour. In this case, the amount of water expelled to drain is reduced.