RPM - Rotations Per Minute

Noise problems can be related to a rotational speed of a machine. In these cases it is interesting to investigate the noise level as a function of how fast the engine is working.
On the right hand side of the Nor150 there is a socket for a rotational speed sensor. A typical input signal to this socket is a pulse train with one pulse per rotation.
The distance between these pulses will give the instrument the possibility to calculate the current number of rotations per minute which is typically used to describe operation conditions for machines and engines. These rpm numbers can be logged with the profile (time) periods.
The RPM sensor can use any type of technology for the pulse detection, as long as it provides a reasonable electric signal.