This UV-Vis optical water quality sensor measures COD, BOD and TSS using full-spectrum absorbance from 190 to 720 nm wavelength. Designed for continuous online monitoring, it features a high-precision photodetector placed at 180° to capture transmitted light and correlate absorbance to organic load and suspended solids. With multipoint calibration function, the sensor delivers accurate results across diverse wastewater and industrial effluent streams.