OIL IN WATER ANALYZER

The measuring principle is based on fluorescence: when lighted at a specific wavelength (excitation), some chemicals re-emit light (emission) at another longer wavelength according to Beer Lambert law. 

Very few chemicals are fluorescent and give a highly selective measurement. The emission light is detected by a high sensitivity photo multiplier to detect very low concentrations from a few ppb(particles per billion). The excitation light is controlled by a detector to compensate any variation of the source.The most generally used OIW analyzers are Forbes Marshal and AWA