HJ 762-2015 "Technical requirements and detection methods for automatic online monitors for lead water quality" stipulates the technical requirements, performance indicators and detection methods of automatic online monitors for lead water quality. This standard applies to the production design, application selection and performance testing of such instruments. According to the different monitoring environments, it is divided into two types of instruments: Type I is suitable for surface water, groundwater and drinking water, etc., with a detection range of 0.005~ 0.2 mg/L; Type II is suitable for domestic sewage and industrial wastewater, etc., with a detection range of 0.2~ 2 mg/L. The standard refers to a number of relevant documents, including GB 4208 "Protection level of enclosure (IP code) " and GB/T 7470, GB/T 7475 and other water quality analysis method standards.