The liquid level sensor is a pressure sensor that can measure the level of liquid, it is one of the important sensors in modern society, and it is widely used in many fields. The liquid level sensor has a simple structure, easy installation, reverse protection function, and a relatively long service life, so it is favored by the market.
How many types of liquid level sensors are there?
Common liquid level sensors have the following types, and the practicability of these types of liquid level sensors is also relatively strong, the following are common types of liquid level sensors: photoelectric liquid level switches, capacitive liquid level sensors, ultrasonic liquid level sensors, etc.
1. Photoelectric liquid level sensor.
There are a number of technical terms used to describe the level sensing technology of photoelectric level sensors. For example: optical prism, electro-optics, single-point optics, optical level switches, etc., the following is a brief introduction to the term photoelectric level sensor
The photoelectric level sensor consists of an illuminated LED and a phototransistor. When the sensor tip is in the air, the infrared light within the sensor tip is reflected back to the transistor detector. When in a liquid state, infrared light is refracted from the tip of the liquid sensor, reducing the amount of energy reaching the detector. As solid-state devices, photoelectric level sensors are ideal for a wide range of advanced sensing applications, especially where stability is important. Optical level sensors are suitable for high and low water level detection in large and small tanks. It is also suitable for detecting liquid leaks and preventing damage to valuable equipment.
Advantages: Compact, no moving parts, resistance to high pressures and temperatures, plus the ability to detect very small amounts of liquid.
Disadvantages: Due to the direct contact with the liquid when the photoelectric level sensor is used, it needs to be connected to the power supply, and some viscous substances will remain on the prism to cause false alarms.
Applications: Container, tank level measurement and leak detection applications.
2. Capacitive liquid level sensor.
Capacitive level sensors work in such a way that the process fluid has a significantly different dielectric constant than air. The change in capacitance between the two plates due to the horizontal change is measured between them. There are two versions of the capacitive level sensor, one for fluids with a high dielectric constant and the other for fluids with a low dielectric constant, and the capacitive level sensor for a wide range of solids, liquids and mixed materials. They are also available in contact and non-contact configurations, which means that some of them can be attached outside the vessel. When selecting a capacitive level sensor, it needs to be calibrated according to the specific detection object to prevent differences in different dielectric constants and containers. Contact capacitive level sensors are based on direct contact with the liquid being detected, so the fluid adhering to the probe can significantly affect the stability of these sensors.
Advantages: non-contact, compact structure, accurate detection.
Disadvantages: Calibration may be required and can only be used in some liquids.
Application: Tank level monitoring in the chemical, food, water treatment, power and brewing industries.
3. Ultrasonic liquid level sensor.
Ultrasonic sensors measure the time it takes for a water level relative to the distance between the sensor and the liquid by calculating the duration and intensity of the high-frequency sound waves reflected back from the surface of the liquid. The length of time it takes for the sensor to react is affected by various factors in the atmosphere above the medium, such as foam, temperature, etc. Therefore, the installation location is very important in ultrasonic level sensors.
Advantages: No moving parts, compact design, reliable detection, independent of media characteristics.
Cons: Relatively expensive, invasive, performance can be affected by various factors in the environment.
Application: Non-contact applications with high viscosity and solid particles for the inspection of systems that require remote monitoring.
After reading this article, I believe you will also be able to better understand the application of liquid level sensors and their common types!Today, with the increasing development of sensor science and technology, liquid level sensors have attracted many users with their good stability, high reliability, economic and durable characteristics, and now, their market applications are becoming more and more extensive.