CF-5200 Frequently Asked Questions

Question number FAQ-0547

I'm performing an FFT on the vibration waveform in the 500Hz range, but it's not showing up on the display. When I turn off the digital filter, it displays around 250Hz, but I don't know why.

We can conclude that there are no signals below 500Hz.

The digital filter is an anti-aliasing filter (low-pass filter), and because it is OFF, the 750Hz component appears at 250Hz due to aliasing.
Always use with the digital filter turned on.
Generally, lowering the frequency range from 100kHz ensures that signals in the higher frequency range are not overlooked.
If you suspect the data is incorrect, try changing the frequency range and voltage range before measuring again.

Related instruction manual chapters

3.5 Anti-Area SIG Filter

Last updated: 2000-04-10