Arrangement for harmonic-free measurement of the speed of an elastic material web transported via a row of rollers

The invention relates to an arrangement for harmonic-free measurement of the speed of an elastic material web, transported via a row of rollers, by means of tachometer generators mounted on the rollers. The invention consists in that an even number of tachometer generators are mounted on rollers which are not immediately adjacent, and between which an odd number of rollers are situated, and in that the measured value for the speed of the belt is formed from the arithmetic mean of the measurement signals of the tachometer generators. The tachometer generators are arranged as far as possible in the middle of a drive group. It is preferable to provide two tachometer generators. One roller is preferably situated between the rollers provided with tachometer generators. The selection of the rollers whose speeds are measured is performed in such a way that the natural vibrations of the system are contained in phase opposition in the measurement signals.