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Accelerometer response

Accelerometer response

Accelerometer response

(OP)
In what form is the accelerometer responds during random vibration? Or in other words, how does the response plot looks like? Is it in g vs Hz or g^2/Hz vs Hz or g vs  time? A known PSD profile is input and the area under the plot is G rms.
Thanks.

RE: Accelerometer response

Whatever are you talking about?  

An accelerometer measures acceleration, hence, its output is acceleration, usually in mV/g.

PSDs are processed from the raw data.

TTFN

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RE: Accelerometer response

(OP)
Thanks a bunch. I know that accelerometer gives data in volts/g. But I would like to know how the PSD is derived from the raw data. Do I have to know the resonant frequency of the system? And do I have to know the transmissibility? Please explain.

RE: Accelerometer response

(OP)
No. I am trying to understand the process because I have never done a vibration test analysis before. Please help.

RE: Accelerometer response

The response plot will look like whatever you inputed, so if you used g^2/Hz, then that's what you will get out.  If you happen to have a resonance at 1000Hz, then there will be a spike at that frequency in g^2/Hz.   

RE: Accelerometer response

To be a bit more specific than IRstuff, you need to review Fourier transforms, and then discrete Fourier transforms.  These transform time-based data functions (or series of discrete time-based data points) into frequency space.

 

RE: Accelerometer response

A PSD producing program takes in acceleration (vs. time) in g's and produces a plot with units of g^2/hz on the vertical axis and frequency on the horizontal axis.  That plot tells you where the energy of the signal is.  If there is a peak near 10 hertz then you might have a resonance near that frequency (or just a lot of activity near 10 hertz for a reason other than resonance).  The sharpness of the peak gives an indication of the damping at that frequency.

RE: Accelerometer response

I don't disagree, IR - but somebody else may stumble on these posts and wonder...

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