The TSS Sensors TR80 (with wiper blade) and TR82 (no wiper blade) use an optical method for determining the turbidity, a light beam is directed into the sample where it is scattered by suspended particles in the water. The amount of scattering depends on the amount of material in the water, the wavelength of light used, and the size and composition of the suspended particles.
Three detectors monitor the light beam at an angle of 90°. The first detector inside the sensor is the reference detector that compensates for changes in the LED light source caused, which is caused by aging or other variations. The second detector measures a short path length, which is best for high concentration measurements, % concentration and g/L. The third detector measures the longer path length which is best for lower concentrations, FNU and ppm. The turbidity signal is constantly adjusted versus the reference detector and digital filter functions help to suppress interfering signals, while the self-monitoring diagnostics assure a highly reliable measurement.