Ultrasonic liquid level gauges can use two-wire, three-wire or four-wire technology. The two-wire system is: the power supply and signal output are shared; the three-wire system is: the power supply loop and the signal output loop are independent. When using DC 24v power supply, a 3-core cable can be used, the negative terminal of the power supply and the negative terminal of the signal output share a core wire; the four-wire system is: when AC 220v power supply is used, or when DC 24v power supply is used, and the power supply loop and the signal output loop are required to be completely isolated, a 4-core cable should be used. DC or AC power supply, with 4~20mADC, high and low switching output.

Measuring range: 0-50 meters, multiple forms available, suitable for various corrosive and chemical situations, high precision, remote signal output, PLC system monitoring.

The working principle of ultrasonic level gauge is shown in the figure. Ultrasonic level gauge generally uses a ceramic ultrasonic transducer that combines transceiver and receiver. The transmission and reception of sound waves are completed by the same probe. The probe emits an ultrasonic signal to the liquid surface to be measured. The ultrasonic wave is propagated from the probe to the liquid surface to be measured through the propagation medium, and is reflected on the liquid surface. The reflected wave propagates to the probe along the original path and is received by the probe.