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Relative displacements during random vibration

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NaikD

Mechanical
Joined
Nov 23, 2002
Messages
48
Location
US
Hi,

I need help regarding test setup for determining relative displacements using accelerometers at two locations during random vibration.

We had done this before about 6 years back but I have forgotten the details.

1. Install two accelerometers at two locations
2. Take output from the two accelerometers to charge amplifier/summer to get the difference
3. Retrieve PSD v/s frequency data and then double integrate to get the relative displacement PSD v/s frequency at the two locations. Then calculate rms displacements.

Is this correct?

Thanks in advance for your help.

Regards,

- NaikD
 
Yes, although obviously you need one to point the opposite way if you want the difference, not the sum.

Usual provisos apply, double integration is not straightforward. If you are using B&K 2635 charge amps read the instruction manual it is quite informative on this.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
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