Fault frequencies are very important in vibration analysis because they allow the analyst to correlate vibration data to specific components in the equipment that may be in some stage of failure (equipment faults). Fault frequencies change with any adjustment in the speed of the equipment being monitored. Most modern vibration data collectors and software will automatically re-calculate the displayed fault frequency information as the rotational speed of the equipment changes. Component information (bearing information, gear information, etc.) is required to calculate and display the fault frequencies of specific components in machinery.

It is important to create fault frequency setups at the beginning of a vibration analysis program. Not doing so will affect the overall success of the vibration analysis program.