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bsr201283

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Dear All, 

We are developing accelerometer for vibration analysis. Accelerometer have frequency range (bandwidth) from 0 to 2.7 KHz. 

When I test this product with bandwidth 2.7kHz in normal motor with small load on shaft ,I got the acceleration in the range of X- 10 m/S2  , Y - 6.5 m/S2 and Z - 3.5 m/s2.

Now i decrease the bandwidth to 500 Hz and tested on same motor , i got same values as mentioned above.


Now I moved to Diesel Generator test the vibration. 

With bandwidth (dc to 2.7 kHz) , I used to get acceleration values of X- 45 m/S2  , Y - 63 m/S2 and Z - 41 m/s

But with bandwidth (dc to 500 Hz) , I used to get acceleration values of X- 20 m/S2  , Y - 21 m/S2 and Z - 36 m/s

Now the doubt is which values  I can proceed with when accelerometer on diesel generator???????????????? what is the bandwidth requirement for Diesel generator and industrial equipments???? 



John from PA

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Reply with quote  #2 
A couple of good resources...

https://energiforskmedia.blob.core.windows.net/media/22075/diesel-generator-set-vibrations-energiforskrapport-2016-339.pdf

https://www.theseus.fi/bitstream/handle/10024/104065/Orn_Johannes.pdf?sequence=1 (scroll into the document several pages to get rid of the text in Finnish)


OLi

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Do you aim to have any anti friction bearing condition monitoring that is 50-90% of the use of the technology? In that case the range is way to low to get reasonable prediction time.
Is the 2.7 kHz limit set by the wish to have the mostly linear part of the sensor range up to 50% of the range up to the resonance? Nobody in this business care about that, everything is very crude in that way I think. Your sensor resonance do also depend on the mounting, numbers in datasheet are for lab, IRL in  the field are very different so they are not correct anyway.


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Walt Strong

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Is this a school project, since there are already a lot of accelerometers of various types on the market? You might consider getting a good quality calibrated piezoelectric accelerometer for reference measurements. Vibration is not measured down to DC.

Walt
RustyCas

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Reply with quote  #5 
Quote:
 We are developing accelerometer for vibration analysis.


Like Walt, I too wonder, why?  Are you re-inventing the wheel?  Or are you trying to somehow produce a "better" accelerometer?

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fburgos

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Reply with quote  #6 
I believe this is about developing, condition monitoring device based on your other posts.

I remember that iso 8528??? Recommends vibration in the range 2-250hz I guess 500 is fine for your application.

For roller bearings 2.7hz frequency rage is ok.

As Walt said dc is a no go, use a proper high pass filter
OLi

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Reply with quote  #7 
If you have a generator at the end of the Diesel, it is a different story. 2.7 kHz give to short warning time for my taste. MEMS sensors in that class do cost or have they dropped in price? Maybe 10 kHz is good enough compromise. I have use 12 kHz for 15+ years and that is good enough so 10 may not make that much difference, maybe.
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