The Pneumercator RSU801F is a single float normally open sensor that detects level changes within the reservoir. A breach of the inner or outer tank wall will trigger an alarm, as the reservoir level changes. Fluctuations due to temperature and barometric pressure changes should not trigger an alarm. Sensor is non-discriminating (one alarm for high and low levels) requiring (1) N.O. input. When connected with a LC2000 or TMS series controller, they support Pneumercator's FAULT-DETECT supervised wiring technology, which automatically detects sensor or field wiring faults.