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Nephelometer
Instrument for measuring the concentration of suspended particulates / From Wikipedia, the free encyclopedia
A nephelometer[1] or aerosol photometer[2] is an instrument for measuring the concentration of suspended particulates in a liquid or gas colloid. A nephelometer measures suspended particulates by employing a light beam (source beam) and a light detector set to one side (often 90°) of the source beam. Particle density is then a function of the light reflected into the detector from the particles. To some extent, how much light reflects for a given density of particles is dependent upon properties of the particles such as their shape, color, and reflectivity. Nephelometers are calibrated to a known particulate, then use environmental factors (k-factors) to compensate lighter or darker colored dusts accordingly. K-factor is determined by the user by running the nephelometer next to an air sampling pump and comparing results.[clarification needed] There are a wide variety of research-grade nephelometers on the market as well as open source varieties.[3]
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