frequency analysis on vibraiton signals

[bon2b]

I'm measuring Acceleration and analysis the frequency of the signal using the following setup:

• measurement device: NI9234 on  cDAQ9172 chassis
• measurement software: LabView SignalExpress 2009 with Sound and Vibration Suite
• accelerometer: ADXL330

Even though I could see a clear vibration signal in time domain measurement as shown in the attached screenshot, I could not locate this signal's frequency in my analysis. All I could see in my power spectrum is the DC component at 0HZ. Did I do anything wrong in my analysis step?

Thanks a lot!

[Ali M]

Hello bon2b,

To better answer your questions, what frequency range are you expecting from your signal(s)? The Project Documentation tab image shows (0-300)Hz, if its higher than this, it may not have been displayed. Can you verify your readings using the Power Spectrum graph (set on autoscale)? This graph can be viewed by selecting the Power Spectrum Step and making sure you are on the Step Setup tab.  

Best regards,

Ali M

Applications Engineer

National Instruments

www.ni.com/support