
Product Number: 2603100
Ultra-Low Range Total Hardness Testing for High-Purity Water
The Hardness (ULR) Reagent Set, Solution Pillows (2603100) is designed for ultra-low range measurement of calcium and magnesium hardness in high-purity water applications using the Chlorophosphonazo colorimetric method (Hach Method 8374, DOC316.53.01044).
This reagent set enables accurate determination of total hardness as CaCO₃ at concentrations far below traditional titration.
Hardness (ULR) Reagent Set, Solution Pillows (2603100) are designed for ultra-low range measurement of calcium and magnesium hardness in high-purity water applications
Key Features & Benefits
Ultra-Low Range Hardness Detection
Measures total hardness over the range of:
8 - 1000 µg/L Total hardness as CaCO₃ using a standard plastic cell (PN 2410222)
Ideal for High-Purity Water Applications
Designed for monitoring trace hardness in:
• Municipal pretreatment
• Membrane protection
• Groundwater and source water monitoring
• Reverse osmosis (RO) systems
• Demineralizer trains
• High-pressure boiler systems
• Semiconductor and ultrapure water processes
• Zeolite water softening system
• Pharmaceutical (makeup water)
Solution pillow format supports approximately 100 tests and is ideal for laboratories and facilities performing routine, ultra-low level hardness monitoring.
Calcium and magnesium ions react with the Chlorophosphonazo indicator to form a colored complex that strongly absorbs light at 669 nm. The addition of CDTA reagent disrupts this complex, and the decrease in color intensity is proportional to total hardness concentration as CaCO₃.
This method provides a highly sensitive alternative to:
• EDTA titration
• AA (Atomic Absorption)
• ICP instrumentation
for ultra-low hardness analysis.