SA Series Capacitance Level Switch

Working Principle

The Fine-tek Capacitance Switch for liquids and solids can be used in mediums such as liquids, pastes, syrups, powders, granules, flakes and chips. It’s broad application and rugged build makes it a highly versatile across all industries. Capacitance switches rely on electrical capacitance theory (the ability of a medium to store electrical energy). When an electrical circuit has two separated conductive plates, the space between the plates acts as a capacitor and stores the electrical energy. Mediums have differing conductivity and dielectric constants which affects their energy sstorage capability. When the switch comes into contact with the medium, it can detect a change in the surroundings and this actuates the switch accordingly. Materials with high conductivity or high dielectric constants such as water tend to have high capacitance. The opposite applies for low conductive substances such as popcorn, wax or air. Thus the switch works well in mediums with reasonably high dielectric constants or conductive solutions.


  • Ground level test function available
  • Max. operating temperature: 800°C
  • Sensitivity and time delay adjustable


  • Standard Type (SA110 & SA111 A/B/C)
    Suitable for general use.
  • Hi-Temp Type (SA120 & SA128 A/B/C)
    Suitable for high temperature environment.
  • Anti-Corrosion Type (SA130 & SA132 A/B/C)
    Suitable for corrosive environment.
  • Remote Probe Type (SA140 A/B/C)
    For use with vibrator equipped with tank.
  • Wire-Probe Type (SA150 A/B/C)
    Suitable for silo or large-size tank.
  • Plate-Probe Type (SA160 A/B/C)
    Suitable for granules and at lower position of tank side.
  • Explosion-Proof Type (SA270 ~ SA279)
    Ex dia II C T4~T6, DIP A21 TA,T3~T6
  • Explosion-Proof Type (SA370 ~ SA378)
    Ex ia IIC T3~T6
    Equipped with SA-75U signal conditioner can be used in hazardous areas.
  • Anti-Static Type (SA180 & SA181 A/B/C)
    Suitable for electrostatic environment
    (It won’t be damaged by the electrostatic discharge)


Datasheet: EN