You searched for: “nephelometer
nephelometer
1. An instrument to register the comparative cloudiness of the sky.
2. A photometer designed to estimate the amount of particulate matter in a turbid medium, measuring light-scattering properties to make comparisons with a series of standard suspensions.
3. In optics, any of various instruments that measure the intensity of light scattered by particles suspended in liquid, in order to determine the amount of material present in the liquid.