The term "liquid level" in liquid level switch refers to the height of the liquid level in an open or sealed container. The "switch" output signals of different liquid levels.
Due to restrictions such as large tank size, inconvenience of human entry, and the presence of hazardous substances in the tank, sensors are essential for accurate measurements. Liquid level sensors are classified into non-contact and contact types based on whether the sensor comes into contact with the measured liquid.
There are several types of liquid level sensors:
1. Continuous Measurement Liquid Level Sensors:
These sensors, also known as liquid level gauges, can be constructed using strain gauges, magnetic elements, capacitive plates, ultrasonic waves, infrared, and other methods. Ultrasonic and radar liquid level sensors, for example, calculate liquid levels by measuring the time difference between emitted and reflected waves. These sensors can be placed outside the container, do not need direct contact with the liquid.
2. Non-Contact Liquid Level Sensors:
Non-contact liquid level sensors include ultrasonic liquid level transmitters that measure liquid level height using ultrasonic echoes, radar liquid level transmitters that measure liquid level using reflected radar waves, and radiation-based level gauges made using nuclear radiation principles.
3. Contact Liquid Level Sensors:
Contact liquid level sensors include immersion liquid level transmitters, static pressure liquid level transmitters, float-type liquid level transmitters that change with liquid level, capacitive liquid level transmitters that change capacitance due to liquid level changes, liquid level sensors based on the magnetic expansion principle, sensors that measure liquid level using electrode height, and sensors that measure liquid level using the principle of vibration of a tuning fork when in contact with the liquid.
Liquid level sensors have become indispensable in fields such as power, petrochemicals, pharmaceuticals, water supply and drainage, and environmental protection. They play a crucial role in the industrial sector and occupy a prominent position.
