HM Digital, PSC-54, Single Line, EC/TDS Mini Controller with 4-20mA OutputThe PSC-54 is a product from HM Digital offering extended range EC/TDS testing for the commercial or industrial water treatment professional. This "mini" controller has an adjustable relay able to control a pump or valve with a 4-20mA output.Features:Extended range for TDS and EC4-20mA output signalTemperature display modeDigital calibrationThe fully adjustable relay control is set by the user to automatically stop a pump or valve if the level rises above the settingStainless steel electrode