FS20701 is a rail-mounted water immersion sensor with an external sensing electrode that uses the principle of liquid conductivity for detection. During normal operation, the two-pole probe is insulated by air; when immersed in water, the probe becomes conductive and the sensor outputs a dry contact signal. When the immersion height of the probe exceeds the set value, an alarm signal is generated. The input power supply, induction wire, and signal output of the sensor are completely isolated.
After powering on the sensor, it will perform self-checking, and it can output monitoring results after about 3 seconds. It adopts the standard MODBUS-RTU communication protocol, and RS485 signal output, which can set the device address, communication rate, and detection sensitivity to meet the detection requirements of different environments. It is widely used in communication base stations, hotels, restaurants, computer rooms, libraries, archives, warehouses, equipment cabinets, and other places where water immersion alarms are required.