The Endress+Hauser Viomax CAS51D is a memosens sensor for optical nitrate or SAC measurement in water, wastewater and utilities. The CAS51D allows unattended operation in a wide range of process conditions. Due to the unique design of the CAS51D, the sensor is extremely robust and it is also low-maintenance thanks to its self-cleaning functionality. With Memosens digital technology, CAS51D combines maximum process and data integrity with simple operation. It enables lab calibration and simplifies predictive maintenance.