Product - Dissolved Oxygen HQd Meters and IntelliCAL™ Probes

Method 10360 for Dissolved Oxygen Approved by EPA for Reporting  

The luminescent dissolved oxygen method utilizing the technology Hach pioneered in 2003 is now fully EPA approved. Hach's LDO process and lab probes, as well as BOD tests conducted with Hach's HQd meter platform can now be used for reporting purposes when following this newly approved method.

Download Method 10360 (PDF) PDF        Final 2012 EPA Methods Update Rule (MUR)

Build Your Own HQd System  

HQd Configurator

HQd Configurator

Hach now has the option of creating your own HQd system to suit your specific testing needs. Choose from options including benchtop or portable, power supply, testing parameter and more!
Build your own HQd System

LDO® Meters & Probes  

Luminescent Dissolved Oxygen: Simplify Your Maintenance

No MembranesThe breakthrough Hach Luminescent Dissolved Oxygen (LDO) technology, now the standard for measuring Dissolved Oxygen, eliminates the numerous reliability and maintenance concerns inherent in older DO membrane instruments.
  • No membranes!
  • Infrequent calibrations
  • No electrolyte to replace or anode to polish
  • 1-year sensor life
  • EPA recommended method

See below for individual meters and probes or see our kits that include everything you need to start testing!

HQd Meters for Dissolved Oxygen  

HQ440D Laboratory Dual Input, Multi-Parameter Meter - pH, Conductivity, Optical Dissolved Oxygen, ORP, and ISE


HQ40d Portable pH, Conductivity, Dissolved Oxygen, ORP, and ISE Multi-Parameter Meter


  • HQ40d Portable
    • - Dual Input
    • - Multi-Parameter - pH, Conductivity, Dissolved Oxygen, ORP, and ISE
  • HQ30d Portable
    • - Single Input
    • - Multi-Parameter - pH, Conductivity, Dissolved Oxygen, ORP, and ISE

IntelliCAL LDO Probes  

IntelliCAL™ LDO101 Rugged Luminescent/Optical Dissolved Oxygen (LDO) Probe, 5-Meter Cable

Rugged LDO Probes

Designed for harsh environments. Features a super-tough, stainless steel body and polymer shroud that protects the sensor from impact. Reinforced, steel-sheathed cables are durable, yet manageable. Waterproof for 24 hours at a depth of 30 meters.

IntelliCAL™ LDO101 Standard Luminescent/Optical Dissolved Oxygen (LDO) Probe, 1-Meter Cable

Standard LDO Probes

Iso measures temperature. Waterproof for up to 24 hours at a depth of three meters.

HQd Bundles for Dissolved Oxygen - Meter and probe bundles  

LDO Method 10360 - EPA Approved