Direct Speed Reading Strobo Scope

* Non-contact speed measurement
* High intensity flashes
* Direct speed reading in RPM
* No shaft modification

Introduction :
Measurement of the speed of a rotating shaft is a common requirement in many industrial and laboratory applications. Such measurements have usually been carried out in the past with the help of contact type tachometers with friction drive. More recently digital optical non-contact tachometers have been designed which count the reflected pulses from a white patch on the shaft and then display the speed in rpm. The light source is usually a filament lamp operating with dry cells leading to limited life and illumination. A similar idea with magnetic pick-up from a particular area of the shaft has also been used for speed measurement.

A third category of speed measurement instruments is based on the stroboscope principle. In this a high intensity light flash of a variable frequency is directed towards rotating shaft. Any marking on the shaft appears stationary, if the time of one shaft revolution is a multiple of the flash period. Earlier stroboscopes used neon tubes of low intensity which forced their use close to the rotating shaft.