The overspeed control sensor CRT30A type is presented an M30 threaded metal sensor with inductive detection with intervention distances between 4 and 6 mm on metallic material. It is used to control the speed acceleration (overspeed) of a rotary or linear movement, verifying that the time detected by the sensor between two pulses does not become less than the one set due to an acceleration caused by a mechanical malfunction in equipment where it is necessary to check that the permissible speed is exceeded. The device contains both the metal-sensitive inductive detection system and the acceleration control system. Furthermore, the power supply voltage of 18÷50Vdc and 18÷240Vac and the exchange relay output make it a compact and practical device for the fitter to use.