Application This method is applicable to wastewater containing ammonia nitrogen within the range of 0–300 mg/L. Excessive calcium and magnesium ions, residual chlorine, turbidity, or other interfering factors may affect measurement accuracy. Technical Parameters Measurement Method Salicylic Acid Spectrophotometric Method Measurement Range 0–300 mg/L Indication Error ≤ ±3% when ≥ 5.00 mg/L; ≤ ±5% when < 5.00 mg/L Repeatability ≤ ±2% Measurement Cycle Minimum cycle is 20