The detection principle of a common liquid level sensor
Liquid level sensor is a sensor used to measure the level of liquids or solids, which is widely used in industry, agriculture, environmental protection, medical and other fields. According to different measuring principles, liquid level sensors can be divided into many types, and the following describes several common liquid level sensors and their detection principles.
1.Capacitive level sensors.
Capacitive level sensors use the capacitance principle to detect the level of a liquid by measuring changes in the capacitance value. It consists of two electrodes, and when the electrodes are filled with liquid, the capacitance value changes. Depending on the rise and fall of the liquid level, the capacitance value will also change accordingly, so that the liquid level can be measured. This sensor is suitable for measuring a wide range of liquids and has the advantages of high accuracy, strong reliability and fast response.
2.Ultrasonic level sensors.
Ultrasonic level sensors use the principle of reflection of ultrasonic waves to measure the liquid level by measuring the time it takes for ultrasonic waves to be emitted and reflected back. It consists of an ultrasonic transmitter, a receiver, and a controller. When the ultrasonic transmitter emits ultrasonic waves, the ultrasonic waves will be reflected back when they encounter the liquid surface, and the receiver will determine the liquid level by calculating the time after receiving the reflected ultrasonic waves. This kind of sensor is suitable for measuring all kinds of liquids, and has the advantages of high accuracy, strong reliability, and fast response, but it is not suitable for harsh environments such as high temperature and high pressure.
3.Radar level sensor.
Radar level sensors use the reflection principle of microwaves to measure the liquid level by measuring the time it takes for microwaves to be emitted and reflected back. It consists of a microwave transmitter, receiver, and controller. When the microwave transmitter emits microwaves, the microwaves will be reflected back when they encounter the liquid surface, and the receiver will determine the liquid level by calculating the time after receiving the reflected microwaves. This sensor is suitable for measuring all kinds of liquids, has the advantages of high accuracy, strong reliability, fast response, etc., and can be used in harsh environments such as high temperature and high pressure.
4.Buoyancy level sensor.
Buoyancy level sensors use the principle of buoyancy to measure the liquid level by measuring the change in the position of the float. It consists of a float and a ruler that rises or falls when the float is subjected to the buoyancy of the liquid, causing a change in the reading on the scale. This sensor is suitable for measuring the level of liquids or solids and has the advantages of simple construction and easy maintenance, but is not suitable for viscous liquids or solids.
5.Optical level sensor.
Optical level sensors use the optical principle to measure the liquid level by measuring the change of the optical signal. It consists of a light source, a lens, and a light-sensitive element. When the light emitted by the light source passes through the lens, it will irradiate the liquid surface and reflect back, and the photosensitive element receives the reflected light and determines the liquid level by calculating the change of the light path. This sensor is suitable for measuring a wide range of liquids and has the advantages of high accuracy, strong reliability and fast response, but it is not suitable for turbid liquids or solids.
In summary, different types of level sensors have different detection principles and application ranges. When selecting a level sensor, it is necessary to select the appropriate type and specification according to the actual needs to ensure the accuracy and reliability of the measurement results.