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Compare Water Level Sensor

The following presents a comparison summary between the various type of water level detection methods. Each has its own advantages and disadvantages.

The section after comparison also talks about the commonly used sensors in the industries.

Technology Float Switch


Optical Capacitive


Image/Video RF/ Microwave
No Water Contact X X X
Non-Electric Contact X X
Suitable for Most Types of Liquid X X X X
Simple to Install X X X X
Simple Water Tank Design X X X
Little Maintainence X X X X
No corrosion/ degrade over time X X X
Analog Output X X X X
Digital Output (npn) X
Dry Contact Output
Wide Water Level Depth X X X X
Low Energy Consumption X X X X
 Low Cost    X X   X       XX  X

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Lowest Cost Water Level Sensor

The magnetic float switch is a widely used as a water level detection sensor. It is simple and is mechanically driven. The float switch consists of a float, magnet and a reed switch which are fairly inexpensive.

The reed switch which will be activated when the magnet is near. The activated reed switch will form a dry contact which indicates that a water level is reached.

The disadvantage of a float switch is that it has to be in contact with the liquid in order to function. For this reason, high-density liquid will not be suitable (one example is thick oil). The float switch also comes with a stainless steel version instead of plastic.

The sensor is rather reliable due to its simple mechanism. It is also a recommended secondary sensor to install for safety purpose even if you are using other methods of water detection.

A magnetic float switch is a simple and reliable.

Check out this page for more information about the float switch as a water level sensing.

Water Level Sensor with Analog Output

The ultrasonic sensor (acoustic sensor) is suitable for applications that require the detection of the water level depth in a tank or the amount of water in the water tank. The water level detected has a higher resolution. This wide water level detection range is also known as a water level sensor with “analog output”.

Check out this page for more detailed information about selecting a ultrasonic sensor for water tank level detection application.

Water Level Sensor Suitable for your Application

There are many types of water level sensors technology available. Each has its own advantages and disadvantages.

Feel free to contact PIC-CONTROL if you are unsure which water level sensing technology is suitable for your application.