This equipment works by measuring the amount of scattered light that results from a beam of high intensity light passing through a water sample. When a beam of light passes through a water sample, light is dispersed by the various components in the water, which include organic matter, suspended solids, and minerals. The higher the level of light dispersion, the less clear the water becomes. Measuring the amount of scattered light is known as turbidity, and a turbidimeter is used to detect this level of turbidity.
To accurately measure the turbidity of a water sample, a turbidimeter is usually equipped with a lens assembly or capsule. This is necessary to focus the light beam on the water sample. These lenses also help prevent this light from being diverted, as light rays would have difficulty passing through the sample if they were not properly focused.