According to the function, the water tank is divided into five types: life water tank, fire water tank, production water tank, human waterproof box and household water tower. The water tank brings benefits to people's life production and also has the following problems:

First, the water tank has no water, and it is discovered when it is used.

Second, because there is no water, the pump is pumping dry, causing burnout

Third, when the container is found to be full of water, the water is still pumping

The following describes an automatic controller for the water level of the water tank, which can realize the following functions: when the water level in the water tank is lower than the predetermined water level, the water pump is automatically started to pump; and when the water level in the water tank reaches the predetermined high water level, the water pump is stopped. Pumping, always keep a certain amount of water in the water tank, neither dry nor overflow, very practical and convenient.

Everyone knows that there are two ways to detect the water level of the water tank: manual inspection, water level detection by electronic sensors. Manual viewing has the disadvantage of being inaccurately positioned, time consuming, and labor intensive, so many tank water level controls are usually solved with sensors.

The water level sensor is a kind of sensor commonly used to detect the liquid level to realize the liquid level control function, and can realize functions such as water shortage protection, waterless alarm, anti-overflow function, and automatic water addition. However, there are many types of water level sensors. Which water level sensors are used in the current equipment? Such as floating ball type water level sensor, photoelectric type, capacitive type and other water level sensors. What are their advantages?

1.The capacitive water level sensor is cheap and small in size and does not directly contact the liquid, but is installed on the outer wall of the water tank. It can detect all kinds of liquids with impurities and corrosive.

2. float type liquid level sensor is simple to operate, the advantage is that the price is cheap, the disadvantage is that the liquid level control precision is low, usually can only be controlled within ¡À3mm or even higher. The float type water level sensor can only be installed on the top or bottom, which limits the product requirements. And the float ball type water level sensor will generate scale after using for a period of time. The scale will cause the float ball to gain weight and affect the liquid level detection accuracy, and it does not meet the food hygiene certification standard.

3.photoelectric water level sensor can be placed up, down, side, oblique installation, waterproof level to IP 64, liquid level detection accuracy, can control ¡À 0.5mm. The utility model has the advantages of small volume, long service life, simple installation process, strong stability and high reliability. The application environment is wide, and it is less affected by corrosive, sediment, floating matter, etc. in the liquid. And the contact liquid area is small, easy to clean and more sanitary

4. Ultrasonic water level sensor: Ultrasonic water level sensor is light in weight, high in detection accuracy, non-contact type detection, and more sanitary. It has the characteristics of safety, long life and high reliability. Wide application environment and various installation methods. Ultrasonic water level sensors are prone to dead zones, and no liquid or objects are detected in the blind zone. The ultrasonic water level sensor is not easy to have obstacles under it, and it is not suitable for ultrasonic water level sensor when there is dust, water mist, liquid which is easy to generate a large amount of foam, or when the liquid is volatile. It is easy to cause measurement error, signal loss, accuracy degradation, and so on. Ultrasonic sensors are more expensive.

5. Electrode type liquid level sensor: The electrode type water level sensor has a simple structure and low price. The electrode type sensor directly uses the resistance of water to detect the water level. The sensor generally uses stainless steel or conductive silicone rubber as the electric conductor, and the packaging process is excellent. Inferiority is directly related to the quality of the product. The electrode type water level sensor generates electrolysis after a long period of use, and the generated electrolytic substance is toxic and affects human health.
The above sensors have their own advantages, so what sensors are generally used for water level control? Generally, the water level sensor is used for detection, and the water level sensor can well detect the change of the water level and send a signal to give a prompt. The automatic watering function can also be realized with the control panel. Therefore, the choice of photoelectric level switch water tank water level control is usually the most suitable water level sensor.

The photoelectric liquid level switch uses the principle of refraction and reflection of light to cause reflection or refraction of light at the interface of two different media. When the measured liquid is in the high position, the measured liquid forms an interface with the switch. When the measured liquid is in the low position, the air and the switch form another interface, because the refractive index of the switch plastic hemisphere and air is very large. The difference is that, in the two interfaces, the intensity of the emitted light received by the internal receiving crystal of the switch is different, that is, corresponding to two different switching states.

The liquid level sensor has the advantages of fast response speed and liquid level control accuracy, and the photoelectric liquid level sensor is a highly reliable liquid level sensor. The photoelectric liquid level sensor can detect the characteristics of multi-directional installation, so the upper, lower, side and oblique installation can work normally. The utility model has the advantages of small volume, small space occupation, contrast and manual inspection, and the same customer detection liquid level is detected by the photoelectric liquid level sensor, but the response speed is fast, the liquid level control precision and the maintenance-free characteristic obviously can make the user experience more. it is good. Therefore, the water level detection of the water tank is very suitable for the photoelectric level sensor.