Minimum time for vibration

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Minimum time for vibration

Postby rwx » Mon Jan 30, 2017 7:46 pm

I read in an older post where the vibration needs to last at least 3 seconds. Is that still true?
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Re: Minimum time for vibration

Postby Martyn » Thu Feb 02, 2017 10:27 am

That will really depend upon exactly what the vibration is, and how you are trying to look at it in the software.
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Re: Minimum time for vibration

Postby rwx » Thu Feb 02, 2017 5:30 pm

The vibration is probably a T1 at about 10 Hz.

It lasts 1-2 seconds with a pause of several seconds between events. The length of the vibration and pause varies some.

I would like the software to analyze the vibration frequency to determine if it is really at T1 frequency or not.
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Re: Minimum time for vibration

Postby Martyn » Thu Feb 02, 2017 11:01 pm

Which scope do you have?

And do you have one of the NVH kits ?
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Re: Minimum time for vibration

Postby rwx » Thu Feb 02, 2017 11:55 pm

I'm trying to help a technician at my local GM dealer. I know they have Pico equipment, but the tech could not pick up the vibration on his equipment. (I'm sure the equipment recorded the vibration, but I'm guessing it was not sustained long enough for the analysis, which I suppose is an FFT, to show it)

When I took him for a ride, he then understood under at what driving conditions the vibration occurred.

I assume they have a NVH kit and a PicoScope 4000 Series Automotive oscilloscope, so lets base the discussion on that.

Thanks

Richard
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Re: Minimum time for vibration

Postby rwx » Sat Feb 04, 2017 5:48 pm

There is another way to go at this: Take an actual recording and snip out a few seconds, then reload that short piece of data to see if the FFT will handle it.

I tried to do that with the sample VW Golf data, but I could not see how to extract a few seconds of data (other than exporting it to a .csv file).

Is there software that will do that?
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