Turbidity is a sensory index, which is reflected by the action of substances in water on light, and turbidity measurement is a qualitative measurement. Turbidity measurement has very good linear performance in the low turbidity range. By using a standardized method with numerical traceability and comparing the turbidity value with the sample, the measurement of turbidity can be completely turned into a quantitative measurement. At present, the accurate measurement value of turbidity is generally obtained by instrumental analysis, that is, by using the principle of optical transmission or scattering, the transmitted light or scattered light signal is photoelectrically converted through a photodetector to convert the optical signal into an electrical signal, and then through calibration Calculate the conversion to turbidity values. Generally, according to different measurement principles, these instrumental analysis methods are divided into transmission method, scattering method and transmission-scattering ratio method. How to find a method suitable for our actual production among these measurement methods requires us to deeply understand the principles of these measurement methods, and then obtain the applicable occasions and measurement limitations of these measurement methods from the principle. With its professionalism and innovation, it has developed and produced excellent mechanical and electronic products, and also produced many conventional instruments used in supporting instruments. The hand-held turbidity meter is one of the important parts, the details are as follows: Turbidity, that is, the turbidity of water, is caused by trace insoluble suspended substances and colloidal substances in the water. The measurement unit used by the ISO standard is FTU (turbidity unit) , FTU and NTU (nephelometric unit). The turbidity meter is based on this principle to measure the turbidity of water. The principle of spectrophotometric measurement of turbidity is that, at an appropriate temperature, hydrazine sulfate and hexamethylenetetramine polymerize to form a white polymer, which is used as a turbidity standard solution, and under certain conditions, it is compared with the water sample turbidity Compare. Turbidimeter (instrument) is a special instrument for measuring water turbidity based on the principle that turbid liquid scatters or transmits light, and it should refer to the instruction manual when using it. The principle of spectrophotometric measurement of turbidity is that, at an appropriate temperature, hydrazine sulfate and hexamethylenetetramine polymerize to form a white polymer, which is used as a turbidity standard solution, and under certain conditions, it is compared with the water sample turbidity Compare. This method is applicable to the determination of turbidity in natural water and drinking water.