The Suspended Solids Sensor ViSolid® is a non-mechanical ultrasound cleaning device, that requires low maintenance. It is factory-calibrated, and has a long-term stability SensorCheck function. The increasing concentration of suspended solids and particles will result to the interference of one to the other. Only selected particles are being reached by the light or detected by the receiving device. Thus, incorrect values are measured. Furthermore, the 90 degree scattered light method that is being used for the turbidity measurement can only be utilized for the purpose of lower concentrations.