What is the working principle of the capacitive liquid level sensor?

- Feb 12, 2020-

1. The working principle of the capacitive liquid level sensor:

Capacitive liquid level sensors use the principle of static electricity. The measurement of such a switch usually consists of one plate of the capacitor, and the other plate is the external appearance of the switch. This external measurement is usually grounded or connected to the machine of the device. When an object moves to the proximity switch, whether it is a conductor or not, due to its proximity, the dielectric constant of the capacitor must be changed, so that the capacitance is changed, and the state of the circuit connected to the measuring head is also changed, so you can control the switch on or off. The objects detected by this proximity switch are not limited to conductors, and can be insulating liquid or powder objects, etc.

image

2. Application of capacitive liquid level sensor:

Capacitive liquid level sensors are widely used in home appliances and industrial automation production. Such as humidifiers, mopping machines, water purifiers, coffee machines, water dispensers, water heaters, automatic feeding production lines, etc. are used. 

image


3. Wiring method of capacitive liquid level sensor:

Two-wire system, the load must be connected in series to work in the sensor.

In the three-wire system, the power and load of these sensors are connected separately.

Four-wire system, these sensors are the same as the three-wire system, but provide both a normally closed and a normally open output.