The Fmax and Fmin values set the maximum and minimum frequency limits for your measurements. Equipment with high operating speeds requires a higher Fmax to capture all crucial information. The Fmin (low cutoff) removes very low frequency integration noise from the overall measurement and is normally set at 2 Hz. You can set Fmin to 0, but the minimum value is the second line in the spectrum, where the Fmin value is equal to 2x line resolution.
| Measurement | Recommended setting |
|---|---|
| Fingered elements such as gear teeth, fan blades, pump vanes, and bearing elements | (3 x the number of fingers) x the operating speed |
| Non-fingered elements | 10 x the operating speed |
| Coast up, coast down recordings | 200 to 400 Hz (12,000-24,000 cpm) |