Liquid level switch

Just a switch? It should be a bit wasteful. I guess it's just an alarm card attached to the liquid level gauge.

principle: The two probes attached to the outer wall of the container at the required limit positions are used for transmitting and receiving ultrasonic signals respectively. The ultrasonic echo signal is sent to the CPU for processing. When the liquid level exceeds the limit, an over-limit signal is generated.

Ultrasonic liquid level switch is mainly composed of ultrasonic probe and secondary meter. The surface of the probe is close to the corresponding position on the outside of the tank wall of the oil tank or pressure ball storage tank that needs to be limited. Ultrasonic technology is used (the middle of the fork-shaped probe of the piezoelectric crystal is separated by air. A crystal with a vibration frequency of 1.5MHz transmits the ultrasonic signal to the air gap. When the probe is immersed in the liquid, the crystal acoustic wave couples and the FET switch changes state. ), when the liquid level reaches this position, a switching signal is generated, and then this information is transmitted to the test instrument (secondary meter) located in the safe area through the cable. When the liquid level exceeds or falls below the high or low alarm limit specified by the user, the secondary meter alarm light lights up and the horn emits a buzzer to remind the operator to take measures to ensure safe and civilized production.

It would be a bit wasteful to just make switches.