Electronic optical level sensor switch is developed on the infrared technology. It is a kind of low price liquid level switch without moving parts. The Optical infrared level switch is an innovative level measurement solution.It is used for point level monitor and level sensing.It has been widely used for home appliance,lab instrumentation,industry,etc.

The optical level sensor can be almost used for various of tanks. It can monitor the level of high,medium and low. It is suitable for clean liquid with low viscosity.It is NOT used for Easily crystallized liquid or freezing liquid.

Working Principle



The level sensor contains a near-infrared light-emitting diode and a photosensitive receiver. The light by light-emitting diode is led to lens on the head of sensor. When liquid immerses the lens,light is refracted into liquid,as a result, receiver can’t get light or less. Just by sensing the situation changing, receiver can drive inner photoelectric switch for open outer alarm/control wire loop. If there is no liquid, light by light-emitting diode will be directly refracted back to receiver through the lens.

Technical Features

Comparing with other level sensors,the level switch has many good features as below:

  • Simple structure
  • Small size body,can be installed at any direction
  • High accuracy(level):+/- 0.5mm or +/-1.0mm
  • longer life
  • No moving parts,higher performance
  • No need to adjust
  • High sensitivity
  • Small power consumption
  • Almost no influence to medium
  • Good chemical stability:High  temperature resistance, high pressure resistance, corrosion resistance
  • Compliance with ROHS
  • Patent product design
  • Compliance with safety rules

Technical Specifications

  • Power supply:5VDC,9VDC,12V-24VDC,220Vac+/-10%(50HZ/60HZ)
  • Pressure:1.0MPa, 1.6MPa,2.5MPa or bigger
  • High accuracy(level):+/- 0.5mm or +/-1.0mm
  • Output way: High/low electric level;relay;TTL,Transistor E pole,etc
  • Working temperature: -25℃~ +65℃(NOT used for Easily crystallized liquid or freezing liquid)
  • NOTE: Exact value is decided by different model. Please feel free to ask for related brochure.

Optic Electric Water Level Switch Sensor
Typical Application

  • Sanitary appliance,Pump,Bathing
  • Water Heater, Humidifier,Water dispenser
  • Medical equipment and instrumentation
  • Analytical instruments, Lab instruments
  • Oil level monitor of Compressor and others in refrigeration system
  • Key level monitor of industry application
  • Other electronic level monitor without moving parts

Body Structure Explanation

The optical level switches are usually integrated type with small size body.

But in order to meet special requirement, we also make separated type which has the following advantages:

a.Make control wiring part is apart from water container. Meanwhile, its sensitivity,accuracy and working life is not influenced.

b.Improve fault-tolerant rate.Even though there is deviation between water container and  sensing parts,the level sensor switch can still work well within allowed range.


Idea to Replace Magnetic Float Level Switch

Magnetic level gauges mainly have magnetic level switch,magnetic float switch,magnetic level sensor,magnetic level indicators and level transmitters. They utilize reed switch to monitor water level and has been an often used solution.But as it has moving parts,its reliability and working life is not very ideal.

In order to make comparison within the two level switches, we list their advantages/disadvantages as below:

1.Optical level switch has no moving parts to contact level. Magnetic float level switches have to borrows buoyant force to move float ball part up/down,then to trigger reed switch and sense level.And the float ball may be seized to stop by water scale and no-proper installing.

2.Optical level sensor has a small size body and good unity.It can be installed at any direction. However,magnetic float switch is bigger in size and has moving parts.It has a poor unity. It can be only installed at up/down direction.

3.Optical level sensor is not influenced by magnet,heat energy,vibration,etc. But magnetic level switch has a bigger reaction toward magnet and cast iron parts nearby. Its own magnet part will lose magnetism easily influenced by heat energy and vibration.

4.The electronic level sensor can test 1mm above the bottom of water container.Because of float&magnet weight,magnetic float switch needs certain water depth to make it float.As a result,the low level will be influenced. If want lower level,it will have to design a big pit which increases cost and working time.

5.Accuracy of electronic level switch is +/-0.5mm.

Accuracy of magnetic level switch is +/-2.5mm.

6.Standard life of electronic level switch is not less than 50,000 hours.

Standard life of electronic level switch is 10,0000-20,000 hours.

By the comparison,you should easily notice that optical infrared level sensors are much better than magnetic float level switch. With our rich experience, we have manufactured the electronic level switches with very high cost-effective solution. Thus, it is your good chance to select our level switch sensor for your project or replace existing unreliable float level switches.