HI937521-01 Calcium – Reagents – 50 Tests

Range 0 - 150 ppm | ferrous sulfate method | Resolution 1ppm

The HI 761 uses an adaptation of the USEPA method 330.5. The reaction between the chlorine and DPD reagent causes a pink tint in the sample.

Range 0 - 200 ppb | ascorbic acid method | Resolution 1 ppb

The HI 771 Checker®HC is a simple, accurate, and cost effective way to measure ultra-high ranges of chlorine. Designed as a more accurate alternative to chemical test kits, the HI 771 provides quick, accurate results in four easy steps.