Capacitive Sensors (EGE)

A capacitive proximity switch works with a high frequency oscillating circuit that creates an electromagnetic field on the active sensor surface by means of a capacitor.

When a substantial or fluid substance nears this field a capacitance unbalance occurs and leads to a variation of the amplification in the oscillating circuit. If this amplification exceeds a threshold value, a switching signal is generated.

The operating distance is the separation of an object from the active sensor surface at which a switching signal is produced. The operating distance depends on the diameter of the sensor surface. Therefore larger sensors are required for longer operating distances. Many EGE sensors have an adjustable operating distance.