The HI93701-01 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. These reagents follow the DPD Method in which the reaction between chlorine and reagent causes a pink tint in the sample. The intensity of color is determined by a compatible photometer and the concentration will be displayed. The results will be display the concentration of chlorine in mg/L (ppm). These reagents are designed to be used with samples that have an expected range of 0.00 to 5.00 mg/L free chlorine.