A basic magnetic level sensor is a simple yet effective device used to measure the liquid level inside a container or tank. It operates on the principle of magnetic field sensing and utilizes a float with an embedded magnet to determine the liquid level. Here's how it works:
Components: The magnetic level sensor consists of two main components:
a. Float: This is a buoyant object that floats on the liquid surface inside the tank. It is typically made of a material that does not corrode or react with the liquid being measured.
b. Sensor Housing: The sensor housing is mounted on the outside of the tank and contains a reed switch or a Hall-effect sensor. These sensors are sensitive to changes in the magnetic field.
Installation: The magnetic level sensor is installed on the side of the tank, typically at the desired level where the liquid level is to be measured. The float is allowed to move freely inside the tank, rising and falling with the liquid level.
Magnetic Interaction: The float contains a permanent magnet or a magnetizable element. As the liquid level changes inside the tank, the float moves up and down with it. When the float reaches a certain level, the magnet inside it comes into proximity with the sensor in the housing.
Reed Switch or Hall-effect Sensor Activation: When the magnet in the float aligns with the sensor in the housing, it induces changes in the magnetic field around the sensor. For a reed switch, this causes the switch to close or open (depending on the design), while for a Hall-effect sensor, it generates a detectable voltage change.
Signal Transmission: The change in the sensor's state (open or closed for reed switches, voltage change for Hall-effect sensors) indicates the liquid level has reached a specific height in the tank. This information is then transmitted to the control system or display unit, where it can be interpreted and displayed to the user.
Level Indication: Based on the sensor's output, the liquid level can be displayed in various formats, such as a visual level indicator, numeric display, or interfaced with automation systems for control purposes.
Overall, the magnetic level sensor is a reliable and low-maintenance solution for monitoring liquid levels in various industrial applications, including water tanks, fuel tanks, chemical storage, and more. It is particularly useful in situations where the liquid may be corrosive or hazardous, as the sensor itself remains external to the tank and does not come in direct contact with the liquid.