A basic magnetic level sensor is a simple device used to determine the liquid level in a container or tank. It operates on the principle of magnetic field detection and consists of three main components: a float, a guide tube, and a reed switch or Hall effect sensor.
Here's how the basic magnetic level sensor works:
Float: The float is a cylindrical or spherical object typically made of a buoyant material like foam or plastic. It is designed to float on the surface of the liquid inside the container or tank whose level needs to be measured. The float is equipped with a built-in magnet.
Guide Tube: The guide tube is a long, narrow, and transparent tube that is installed vertically inside the tank or container. It provides a pathway for the float to move up and down with the liquid level changes.
Reed Switch or Hall Effect Sensor: At the top or bottom of the guide tube (depending on the design), there is a reed switch or a Hall effect sensor. Both of these are electronic components that can detect changes in the surrounding magnetic field.
When there is no liquid or the liquid level is below the float, the float will rest at the bottom of the guide tube, away from the reed switch or Hall effect sensor. In this position, the sensor detects a low magnetic field or no field at all, depending on the type of sensor used. This indicates a low or empty level.
As the liquid level rises in the tank, the float will also rise with it due to its buoyancy. As the float moves upward, its magnet approaches the reed switch or Hall effect sensor. When the magnetic field of the float's magnet comes close enough, it triggers the reed switch to close or the Hall effect sensor to register a change in the magnetic field.
This change in the sensor's state signals that the liquid level has reached a certain height, and this information can be used to control alarms, monitoring systems, or other processes related to liquid level management.
The basic magnetic level sensor is widely used due to its simplicity, reliability, and ability to function in various liquid environments. However, it is essential to consider the type of liquid being measured, the temperature, and other factors to select the appropriate materials and sensor type for accurate and safe operation.