The water shortage protection function can be realized by detecting the liquid level change by the liquid level switch, thereby achieving the control liquid level. Shenzhen EPT Technology Co.,Ltd is a liquid level switch manufacturer with 16 years of experience, there are many different kinds of level switch.
Capacitive level switch is a non contact liquid level sensor that can be used to detect the liquid level when fitted to the outer wall of the tank. The biggest advantage of the capacitive level switch is that it does not touch the liquid, so the corrosiveness and pressure of the liquid do not affect the operation of the sensor. The disadvantage is that it cannot be used on metal containers, and the wall thickness of the container also affects the sensitivity of the sensor. In this way, we can use the customer's water tank to carry out relevant tests, and adjust the software according to the test results to determine the most appropriate sensitivity.
In addition to the capacitive type, there is another liquid level switch with higher precision and reliability - photoelectric liquid level switch. This type of liquid level sensor has no mechanical moving parts, it is non-mechanical sensor. The photoelectric type uses the principle of optical reflection, which works by emitting light in different states of the air (anhydrous state) and in a liquid (with a water state). When the sensor head is in a water-free state, the head is exposed to the air, and the light is directly emitted back into the sensor through the head light cone. When there is water, the head is submerged in liquid, and the light is refracted in the liquid, just little or no light is reflected back.
The photoelectric iquid level switch can be divided into two types according to the structure, that is separated and integrated. The integrated type is that the sensor must be in contact with the liquid, it is usually used in water heaters, water dispensers, and toilets where the water tank does not move. Separate type is non-contact type detection, the sensor does not touch liquid, it is usually used for equipment that needs to be moved in a water tank such as a coffee machine, a water purifier, milking machine, or electric steamer etc.