Relationship of Vibration Frequency to Order of Vibration
After carrying out the road test as described in this information, the vibration was determined to be either vehicle-speed related or electric motor-speed related. That determination will identify the vibration frequency calculations that should be done.
| Vibration Type | Calculate |
|---|---|
| Vehicle-speed related | Tire-speed vibration frequency, Driveshaft-speed vibration frequency |
In calculating and using frequency readings it is important to remember the direct relationship between Hertz (Hz) and RPM. One Hertz (Hz) is equal to 60 RPM. This is easy to remember. Think of Hertz (Hz) as cycles per second. There are 60 seconds in a minute, therefore multiply the Hertz (Hz) reading by 60 to get RPM. Conversely, divide RPM by 60 to get Hertz (Hz).
Use the Frequency and RPM Calculations Worksheet to calculate system/component frequencies. The worksheet provides the necessary steps to determine each system/component group frequency.