The HI733-25 are high-quality reagents that are pre-measured, allowing for users to achieve fast and accurate measurements with their Ammonia High Range Checker® HC. These reagents follow the Nessler Method in which the reaction between ammonia and reagents causes a yellow tint in the sample. By simply adding 9 mL from the first reagent bottle and subsequently 4 drops from the dropper bottle to the sample, the reaction will take place and the HI733 will determine the concentration from the color that is produced. The results will be displayed in ppm (mg/L) of ammonia-nitrogen (NH3-N). These reagents are designed to be used with samples that have an expected range of 0.0 to 99.9 ppm ammonia-nitrogen. To convert the reading to ppm of ammonia (NH3) multiply the result by 1.214.