Trigger sensors, also known as speed sensors, are used to monitor the current rotation speed of the piston compressor. Among other things, the speed serves as a reference value for signal analysis. For signal acquisition, we recommend installing a trigger CAM on the flywheel of the machine. The sensor is attached to the machine with an angle, for example, so that the Trigger CAM passes the sensor once with each revolution. In this way, the speed sensor provides the reference point for calculating the top and bottom dead center. The speed signal is a decisive factor for the signal analysis of the reciprocating compressor.