A basic magnetic level sensor is a simple and reliable device used to measure the level of liquids in a container or tank. It operates on the principle of magnetic field interaction with a float that moves up and down with the liquid level. Here's a general description of how it works:
Components: The sensor typically consists of two main parts: a stationary housing (probe or tube) installed vertically inside the tank and a float made of a magnetic material. The float is free to move up and down along the length of the probe.
Mounting: The magnetic level sensor is installed vertically inside the tank with the probe extending from the top to the bottom, while the float is allowed to move along the probe's length.
Magnetic Interaction: The float is equipped with a permanent magnet or contains a magnetic material, such as a magnetized reed switch. As the liquid level in the tank changes, the float moves accordingly.
Sensor Detection: The stationary housing contains a magnetic reed switch, Hall effect sensor, or similar magnetic sensing element. These sensors can detect changes in the magnetic field caused by the movement of the float.
Output Signal: As the float moves up or down, it causes a corresponding change in the magnetic field strength around the sensor element. This change is translated into an electrical signal by the sensor.
Level Indication: The electrical signal generated by the sensor is then processed and converted into a level indication, which can be displayed on a local indicator or transmitted to a remote monitoring system.
Calibration: Before putting the sensor into operation, it is often calibrated to match the specific characteristics of the tank or container it is installed in. This calibration ensures accurate level readings.
Applications: Magnetic level sensors are commonly used in various industries, such as oil and gas, chemical, water treatment, and more. They are suitable for a wide range of liquid types, including corrosive and non-corrosive liquids.
The major advantages of magnetic level sensors are their simplicity, reliability, and suitability for both high and low-temperature applications. However, they may not be appropriate for extremely viscous or solid-containing liquids, as these might interfere with the movement of the float or cause build-up on the sensor probe. In such cases, alternative level sensing technologies like ultrasonic or radar sensors might be more suitable.