Generally most of the Portable and Bench type Turbidimeter operates on the nephelometric principle of turbidity measurement.
The optical system (Ref Figure) includes a tungsten-filament lamp, a 90° detector to monitor scattered light and a transmitted light detector. The instrument’s microprocessor calculates the ratio of the signals from the 90° and transmitted light detectors. This ratio technique corrects for interferences from color and/or light absorbing materials (such as activated carbon) and compensates for fluctuations in lamp intensity, providing long-term calibration stability. The optical design also minimizes stray light, increasing measurement accuracy. Working Principle of