Non‐contacting optical sensors for real‐time water quality monitoring

Describes the development of low cost optical sensor systems for water quality monitoring developed under the “LOADMON” EU research programme. It uses two laser diodes as the sources: one emits blue light at 405 nm and the other red light at 670 nm. The former excites fluorescence of organic materials present in the sample and the red light creates a scatter signal from the suspended particles. The system uses a rotating mirror which allows the light spots to be swept across the sample's surface under computer control until they are below the detector.