Re: FFT Frequency Resolution vs. Graph Update Rate of a Vibration Signal

The best tool NI provides for your application is the Zoom FFT.  This allows you to specify the span (frequency range of the FFT) and the zoom (the delta f such as 0.5hz) in the FFT.  The Zoom FFT has a built in buffer, called overlap and allows you to set the overlap so that it updates at the appropriate rate, event though you may need many seconds of data to get the delta-f in the FFT you are looking for.  We package all this and manage units to display the correct units for power density, power, linear, magnitude, rms, 0 to peak, peak to peak, etc.  We even provide a express VI for the zoom FFT and it is also part of the Sound and Vibration Assistant, requiring no programming at all.
 
<a href="http://digital.ni.com/public.nsf/allkb/F70DB3441DC5AB9986256E97005BA825"; target="_blank">http://digital.ni.com/public.nsf/allkb/F70DB3441DC5AB9986256E97005BA825</a>
<a href="http://zone.ni.com/devzone/cda/tut/p/id/6107"; target="_blank">http://zone.ni.com/devzone/cda/tut/p/id/6107</a>
<a href="http://zone.ni.com/devzone/cda/epd/p/id/5505"; target="_blank">http://zone.ni.com/devzone/cda/epd/p/id/5505</a>
<a href="http://sine.ni.com/nips/cds/view/p/lang/en/nid/12152"; target="_blank">http://sine.ni.com/nips/cds/view/p/lang/en/nid/12152</a>
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