A contactless sensor (proximity sensor) is installed in the motor housing. This registers every second stroke of the diaphragm in the pump chamber. This type of stroke counting is independent from the operation mode of the pump. The signals from the sensor can, for example, be transmitted to an available control unit or an optionally available stroke counter. The strokes for the pump can be pre-defined via the stroke counter.

Once the preset stroke rate is reached, the pump is switched off using a likewise optionally available solenoid valve. The strokes can also be captured pneumatically using a pressure sensor. Here, the pressure change in the motor housing is measured behind a diaphragm.

Stroke counters are available in the following models:
SC 1 – Proximity sensor (Namur) with approx. 3.0 m connection cable
SC 2 – Proximity sensor (Namur) with stroke counter
SC 3 – Proximity sensor (Namur) with stroke counter and intrinsically safe isolating amplifier in accordance with potentially explosive areas
SC 5 – Pressure switch (1.0 – 10.0 bar) with approx. 5.0 m connection cable
SC 6 – Pressure switch (1.0 – 10.0 bar) with stroke counter

If the proximity sensor (SC 1) is used in a potentially explosive area, an intrinsically safe isolating
amplifier should also be provided.