Finder Level Control Monitoring Relay, 72 Series - Finder 72.01.8.240.0000, The Finder 72.01.8.240.0000 Monitoring Relay is from the 72 Series. This Level Control Relay is for measuring Conductive Liquids. The level control relay works by measuring the resistance through the liquid, between the common (B3) electrode and Min. and Max. electrodes (B2 and B1). If the tank is metallic, then this can be substituted as the B3 electrode.The 240V AC 1 CO (SPDT) 10A relay has a Sensitivity Range between 5 to 150kthat is adjustable. There are selectable switches for both the delay time switch and the emptying or filling functions.Care must be taken to ensure that the liquid has a suitable resistivity. Suitable liquids include city water, well water, rainwater, sea water, liquids with low-percentage alcohol, wine, milk, beer, coffee, sewage and liquid fertilizer. Unsuitable liquids include fuels, liquid gas and paint. Finder 72.01.8.240.0000 10A Level Control Monitoring Relay SPDT-CO 240VAC