Order FFT vs Time FFT Waterfall Plots

  • Software
  • Order FFT vs Time FFT Waterfall Plots
Kierstein Casto

Posted on 16.07.2019 20:54

Hello!


I recently recorded some data using the Order Tracking Math module within DEWESoft. The data collected was plotted on an Order FFT Waterfall plot and a Time FFT Waterfall plot, as shown below.





As shown above, the amplitude of the accelerometer do not match between the two waterfall plots. The screen below shows the OT setup.



After going through the Pro Training Order Tracking Course, I see in the example provided the amplitude matches between the two waterfall plots. Is there an error in my setup/settings that would cause the mismatch in my data above?


Thanks in advance,

Kierstein

Jernej Sirk
NVH Application Engineer
Posted on 17.07.2019 08:43

Dear @Kierstein Casto,


Would it be possible to send us your datafile where you see those differencies? I tried to see the same phenomena on my computer with datafiles, but the values are matching.


Best regards,


Kierstein Casto

Posted on 18.07.2019 13:22

Hello!


I tried attaching the data file but the file exceeds the max allowable attachment size (zipped data file is 13.05 MB). Is there another way I could send it?


Thanks,

Kierstein

DEWESoft Support
Technical support
Posted on 18.07.2019 13:25

Dear Kierstein,


attached you will find the instruction on how to upload big files.


Regards


Attached files:
Kierstein Casto

Posted on 18.07.2019 13:31

Thank you so much! I have attached the data file through the private forum.


Kierstein

Kierstein Casto

Posted on 30.07.2019 18:42

Hello!


Just following up - were you able to receive the setup file via the private forum?


Thanks,

Kierstein

DEWESoft Support
Technical support
Posted on 31.07.2019 09:21

Dear Kiersten,


the difference that exist in your datafiles between values on the FFT waterfall and Order waterfall is a normal behaviour. The input into these two visual controls is not the same signal.


In Order waterfall, the FFT is calculated from resampled order domain data


If FFT waterfall, the FFT is calculated from time domain data of the direct input data.


Therefore, the difference in the amplitudes exists


Best regards,

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