Reagents for Freshwater Alkalinity HI 775 Checker HC ®, 25 Tests

Range 0 - 600 ppb NO2-N | EPA method 354.1 | Resolution 1 ppb

Range 0:00 to 2:00 ppm | EPA method 340.1 | 0.01ppm resolution

Range: 0 to 300 ppb. The HI 749 Checker®HC is a simple, accurate, and cost effective way to measure low ranges of chromium VI in fresh water. Designed as a more accurate alternative to chemical test kits, the HI 749 provides quick, accurate results in four easy steps. The HI 749 uses an adaptation of the ASTM Manual of Water and Environmental Technology, D1687-92, Diphenylcarbohydrazide method. The reaction between chromium VI and the reagent causes a purple tint in the sample.