Vibration sensors built to survive in grease and grime and pick up gear mesh faults

The sensor has to be chosen based on calculated gear mesh frequency and bearing defect frequencies. The gear mesh frequency is easily determined by multiplying the number of teeth on a gear by the rotational frequency. For example, a motor with 1800 rpm (30 Hz) and a gear with 50 teeth results in a gear mesh frequency of 1500 Hz. This result multiplied by a factor of 3.25 will provide the maximum frequency the sensor should be able to measure for best results. If the number of teeth on a gear is unknown, as a rule of thumb, the maximum sensor frequency should be assumed to be 200 times rpm (in Hz).