7. Conclusion

When it comes to measuring rotational speeds, the most important thing is to choose the right equipment for the job, without resorting to devices whose performance is much higher than necessary. For this, we have a choice of :

• photoreflective tachometers for non-contact measurements, which allow high speeds to be measured, often without having to remove protective covers;

• contact tachometers, which are used for speeds generally not exceeding 10,000 rpm, and are fitted with a specific tip for linear speed measurements;

• stroboscopes with a speed range similar to that of contact tachometers, but with the advantage of non-contact measurement.

For specific applications, particularly those requiring low uncertainties, the user may have to design...