Measurements of rotating speed let estimate productivity and speed of machines or their movable elements.
Inverters are very often used for regulation of motor rotations in many systems. If the invertor has an analogue output, that is credited to the rotating speed, than the signal can be connected with an indicator, a regulator or a recorder.
Beacuse of often used transmissions and skids, the rotating speed that is given in the system can be differen than the invertor shows. To be sure, you should measure directly on the executive elements.
In such a system, the tachometer is the most important element. It changes the measured values (quantity of impulses) into quantity of rotation in the time unit. Depending on the required accuracy of the measurement and on the rotating speed following appliances can be connected to the tachometer: rotating-impulse converter placed on, for example, motor shaft or proximidity sensor that detectes for example elements of the cog-wheel.
Special made board tachometers can be used as converters of impulse sequence (from above given sensors) into analogue signal with local readout.
Tachometers can show the productivity of cycliccaly working machines, for example machines that pack, calenders or clamps. Connected at the input appropriate sensor count the number of done cycles and on the tachometer you get the readout of the productivity in the time unit.