A water level sensor is used to monitor the liquid level in various tanks. These devices are used to prevent flooding, to control the rise of water at dams and reservoirs; in everyday life they are used in washing machines, when organizing water supply and heating systems, etc.
Classification and Description
Depending on the measurement method, these devices can be divided into contact and non-contact. The water level sensor of the first type is located directly on the wall of the tank, it switches contacts when the liquid reaches the mark on which it is placed. In addition, the measurement of the water level can be carried out by the following methods: capacitive, magnetic, optical, ultrasonic, etc. The optical water level sensor has no moving parts, it is mounted on the tank wall and is triggered when the set level is reached. Interruption of optical rays causes a change in the signal at the output of the device.
The water level sensor (float), is a universal precision device designed for a wide range of different applications requiring ultra-precise measurements of fluid flow. Such devices are single and multi-level, as well as linear (analog).
A non-contact water level sensor can work with various liquids, bulk solids and materials with varying degrees of toxicity and viscosity. Such devices are divided into ultrasonic and capacitive devices.
Contact devices (level gauges) have contact with the liquid that they measure. They can be immersed in water (as radar or hydrostatic) or embedded in the tank wall at a given height (optical, fork vibrating devices). They are optical, piezoelectric forklift, radar or radar, hydrostatic and fiber optic.
How to make a tank water level sensor?
If you are not satisfied with products sold in stores, try to make such a device yourself, especially since it is quite simple. The sensor, brought to your attention, is used to monitor the liquid level in various containers. At the signal of this device, the water pump or the alarm is turned on or off. The device is an elementary DC amplifier, which is made on two transistors. A tuning resistor allows you to set the required sensitivity of the device. Transistors are protected by a semiconductor diode. The device provides an indication in the form of a single LED located on the collector of the first transistor. For assembly, we need resistors (220 kOhm, 10 kOhm - 3 pcs., 1.2 kOhm), one capacitor (470 μF / 50 V), two transistors (BC547), a diode (1N4001) and one LED. This circuit is powered by a constant voltage of 6-15V and consumes an electric current of 75 mA.
As a sensor, you can use plates made of foil fiberglass (10 x 50 mm). They must be set at a distance of 3 mm with foil inward.
Conclusion
Summing up, we note that such devices are very useful, especially in the private sector. Judge for yourself: such a sensor can be installed in a tank for a shower or bath, when organizing irrigation in the garden, as well as in the storage water systems of your home.