Nephelometer

A nephelometer is an instrument for determining the suspension of small particles in a liquid or gas colloid.

It consists of a light source and a photo sensor at a right angle to the light beam is arranged (see nephelometry ). The particle density is obtained from the amount of light reflected from the individual particles. This amount depends in turn on the nature of the particles from ( shape, color, reflectivity ). A correlation between the turbidity and suspended solids is therefore vary from case to case.

A more commonly used in water treatment name for this instrument is turbidimeter. On the market there are different methods of construction, which differ only in the arrangement of light source and photo sensor. A nephelometric turbidimeter measures only the reflection of the particles and non- attenuation of the light beam by the turbidity. The unit of turbidity measured with a calibrated nephelometer is NTU ( Nephelometric Turbidity Unit ).

Gasphasennephelometer be used for the investigation of (planetary ) atmospheres. They provide information on visibility and albedo ( a measure of the reflectivity of non-specular surfaces).