Universal multi-make tool for optically measuring belt tension in Hertz. Using laser technology, the tool may be used regardless of the type of environment, with several applications (conveyors, air conditioners, industrial fans, compressors, generating sets, combustion engines, household appliances, farm machinery etc.). An LED sensor measures the tension thanks to the vibrations of the belt, over a wide range from 5 to 500 Hz. Indication (pictogram) of correct tool positioning by detecting the measuring distance. May be used in noisy environments. Test tuning fork supplied.