Sensors for factory automation hero

SQ4 leak sensor

Safety liquid leak sensor, type 4.

Safety liquid leak sensor, type 4

SQ4 series safety leak sensors detect leaks and thereby curb danger resulting from them. The two-part design, consisting of the sensor and the mounting bracket, simplifies installation. The sensor itself incorporates two-stage detection: a detection unit at the front of the sensor issues a warning if it comes into contact with liquid, whereas if the detection unit in the center of the sensor becomes immersed, the leak is considered critical and the sensor initiates an emergency stop. To provide utmost flexibility, a chemically resistant version is also available. Up to 4 safety liquid leak sensors can be connected to the SQ4-C11 controller.


  • Two-stage detection (mild leak, critical leak)
  • Type 4, PLe, SIL3 (with SQ4-C11 controller)
  • Chemically resistant housing (PFA)
  • Operation also possible without controller


  • Mounting bracket
  • Controller

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Typical application

SQ4 leak sensor
  • Leakage monitoring during wafer production