The HJ/T 102-2003 standard specifies the technical requirements of the total nitrogen water quality automatic analyzer, which is suitable for the development, production and performance inspection of automatic analytical instruments for surface water, industrial sewage and municipal sewage. The standard covers the technical performance requirements and performance test methods. The standard cites GB11894-89 on the method of alkaline potassium persulfate digestion Ultraviolet spectrophotometry for the determination of total nitrogen in water quality. The terms and definitions section includes related terms such as sample, correction liquid, zero point drift and range drift to ensure the accuracy and Stability of the automatic analyzer in the measurement process.