Nephelometer

Part of speech: noun

Definitions

1. An instrument that measures the cloudiness of a liquid or the concentration of tiny particles suspended in a gas by analyzing how they scatter light
2. A device used in laboratories and environmental monitoring to gauge how turbid a fluid is through the light scattered by particles within it
3. A optical measuring tool that determines the density of suspended matter in water, air or other media by detecting scattered light

Etymology: Nephelometer is a straightforward technical coinage: it combines the Ancient Greek "nephélē", meaning "cloud", with "-meter", a suffix from "métron", "measure". The word describes an instrument that measures how cloudy or turbid a liquid or gas is, by gauging how much light its suspended particles scatter. The Greek elements were old, but the compound itself is modern. Scientists assembled it from classical parts to name a new device, as they did with many nineteenth- and twentieth-century instruments. The "-meter" ending follows the same pattern as "thermometer" and "barometer", and it reached English through French "-mètre" from the same Greek root.