Nowadays, many industries require the detection of water turbidity, so turbidity meters are often used in water plants, power plants, industrial and mining enterprises, laboratories, and field inspections. The suspended and colloidal substances such as soil, dust, fine organic matter, plankton, etc. contained in water can cause turbidity in previously colorless and transparent water, and the degree of turbidity of water is the turbidity of water. When in use, the turbidity meter will use a certain amount of incident light to strongly pass through different turbidity water samples of the same thickness. Part of the incident light is absorbed and scattered, while the other part passes through the solution.
The scattered light intensity in the 900 direction with the incident light conforms to the Rayleigh formula:
Is=（（KNV2）/λ）×I0
Among them: I0- incident light intensity Is - scattered light intensity N - number of particles per unit solution V - particle volume λ - incident light wavelength K - coefficient Under constant incident light conditions, the scattered light intensity is proportional to the turbidity of the solution within a certain turbidity range.
Instrument analysis will obtain different transmitted light intensities. By measuring the transmitted light intensity and processing it through circuits, the turbidity value of the water sample can be obtained.
The above equation can be expressed as:
Is/I0=K ′ N (K ′ is a constant)
According to this formula, the turbidity of a water sample can be measured by measuring the scattered light intensity of particles in the water sample.