HJ 763-2015 "Technical requirements and detection methods for cadmium water quality automatic online monitoring instrument" stipulates the technical requirements, performance indicators and detection methods of cadmium water quality automatic online monitoring instrument. This standard is applicable to the production design, application selection and performance detection of this type of instrument. According to the different monitoring environment, 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 0.001~ 0.02 mg/L; Type II is suitable for domestic sewage and industrial wastewater, etc., with a detection range of 0.02~ 0.2 mg/L. The standard refers to a number of relevant documents, including GB 4208 "Protection level of enclosure (IP code) " and GB/T 7471, GB/T 7475 and other water quality analysis method standards.