Features: • Non-mechanical ultrasound cleaning • Low Maintenance • Factory Calibrated • Long-term stability (SensorCheck function) Turbidity Measurement according to the Nephelometric Principle: Using this principle, scattered light is measured at an angle of 90 degree. This method is ideal for low and medium range turbidity up to 4000 FNU. In compliance with EN 27027 and ISO 7027, infra red light with a wavelenght of 860 nm is used. This wavelength is outside of the visible range – thus potential coloration of the sample does not effect the measurements.