turbidimeter

A more popular term for this instrument in water quality testing is a turbidimeter.

A nephelometric turbidimeter always monitors light reflected off the particles and not attenuation due to cloudiness.

He developed the nephelometer and turbidimeter and similar instruments that show properties of aerosols and colloids through concentrated light beams.

It is particularly applicable to colloidal mixtures and suspensions; for example, the Tyndall effect is commercially exploited to determine the size and density of particles in aerosols and other colloidal matter (see ultramicroscope and turbidimeter).