The HI93700-03 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. These reagents follow the Nessler Method in which the reaction between ammonia and reagents causes a yellow tint in the sample. By simply adding 4 drops from each bottle of HI93700-03 reagent set to the sample, the reaction between ammonia and reagents causes a yellow tint in the sample will take place. The intensity of color is determined by a compatible photometer and the concentration will be displayed. The results will be displayed in ppm (mg/L) of either ammonia-nitrogen (NH₃-N), ammonia or ammonium based on meter and setting being used. These reagents are designed to be used with samples that have an expected range of 0.00 to 3.00 ppm ammonia-nitrogen.