Calibration Standard HI 770 Checker HC ®

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.

Range 0 - 20 ppm | ESPA method | Resolution 0.1ppm

Range 0:00 to 2:50 ppm | ascorbic acid method | Resolution 0.01ppm

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.