The OPTISYS CL 1100 measuring system consists of the membrane free OPTISENS CL 1100 sensor. The sensor is characterised by standardised design, easy handling and a long life cycle. Together with the MAC 100 signal converter, flow-through holders, valves, temperature sensor and an optional pH sensor OPTISENS PH 8500, this is a tested and pre-wired measuring system which is very reliable and easy to maintain.