The difference between the level switch and the level sensor

- Nov 02, 2019-

The level switch is a controller that opens the inlet valve according to the signal output of the level sensor and keeps the water level constant.

It can also be said that the liquid level switch outputs a kind of switching signal. The liquid level switch first determines the height of the liquid level, and outputs the switching signal according to the height.


The liquid level sensor outputs a form in which the height of the liquid level is converted into an electrical signal. We can process the electrical signal such as plc, data collector or professional display to output the height of the liquid level.

There is also the same principle of the level switch and the level sensor. However, the liquid level switch is a switch control circuit, and the liquid level sensor is a circuit element equivalent to a transformer and a converter.


In contrast to the characteristics of the optical level sensor:

l, no mechanical moving parts, high reliability

2, small size, can be installed in any direction

3, high liquid level control accuracy

4, in line with safety standards

5, in line with RoHS requirements


Compared with ultrasonic level sensor:

1. The optic level probe sensor is small in size and compact in structure, so the space required for installation is small, and the installation process is simple. The existing float type liquid level switch has a large volume, a loose structure, a large space required for installation, and a complicated design and installation.

The magnetic float level switch pushes the float of the magnet up and down by the buoyancy of the liquid, so that the internal reed switch is opened and closed, so the float has a certain water level, so that the minimum liquid level will be greatly limited. This level switch does not have this limitation.

2. The optic level probe sensor can be placed on the upper, lower, lateral and oblique installation, while the existing magnetic float level switch can only be placed on the upper and lower.

3. The optic level probe sensor level control precision is high within ±0.5mm, and the existing magnetic float level switch has an accuracy of ±3.0mm or even higher.

4. no friction, mechanical moving parts, so the reliability is high, and the existing magnetic float level switch float is extremely easy to be stuck and cause bad.

5. the head is smooth, easy to clean.

6. built-in emitter diode and phototransistor, so long life.

7. The live parts are completely isolated from the controlled liquid, and there is no safety hazard.