This product uses salicylic acid spectrophotometry to determine ammonia nitrogen. In the presence of sodium nitroferricyanide, ammonium reacts with salicylate and hypochlorite ions to form blue compounds. Through photometric colorimetry, ammonia nitrogen is achieved. Full automation of the concentration detection process. The instrument can eliminate the interference of sample turbidity, chromaticity, substrate interference, and other factors in the results of ammonia nitrogen determination. The detection limit of ammonia nitrogen can reach 0.02mg/L, realizing high precision, low detection limit, high stability, and low maintenance of ammonia nitrogen. Fully automatic online monitoring.