Digikey’s catalog listed an inexpensive single axis model part #MSP1001 that cost less than $25.00. This seemed the ideal part to play with. It is a small ceramic package with three leads. It is designed to be glued onto a test surface unlike the more general purpose units that can be screwed on. There is even an optional preamp available.
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compoared with this :
ACH-01?Vibration Sensors?Piezoelectric Embedded Accelerometers?Measurement Specialties
which has better frequency response ?
They're basically a piece of film, typically a couple of cm on a side, which you can tape on to the panel you're measuring. Google can be your friend here.
If memory serves, they're also made by Measurement Specialties.
edit: Your link is to a packaged version. MSI makes them in other form factors as well.
If memory serves, they're also made by Measurement Specialties.
edit: Your link is to a packaged version. MSI makes them in other form factors as well.
does it better then this ?
ACH-01?Vibration Sensors?Piezoelectric Embedded Accelerometers?Measurement Specialties
Yes SY the one I pointed to is made by them. It is now up to $40. Unless he can buy in quantity or get a sample the rep network probably won't do much for him. So he can buy it at Mouser or Digikey. They are the distributors.
He might find one on eBay, but he might also get one of the classic versions that are much more difficult to amplify.
But the really cheap anser is to use a guitar pickup. I did once try ceramic capacitors but the guitar pickup had more than 20 dB better sensitivity.
He might find one on eBay, but he might also get one of the classic versions that are much more difficult to amplify.
But the really cheap anser is to use a guitar pickup. I did once try ceramic capacitors but the guitar pickup had more than 20 dB better sensitivity.
This is certainly doable and has been done before.
The comment that comes to mind is how you will make use of the measurement. If you put the accelerometer on and measure some amplitude signal, what does that tell you exactly? By itself, its only telling you that some vibrations can be measured. That will always be the case, and it is just a matter of the sensitivity of the accelerometer to measure very small vibrations. Are these things calibrated to some absolute amplitude standard or something - I don't know.
The interesting use would be in RELATIVE measurements, e.g. you measure the cabinet panel vibration, then you try to dampen or stiffen the panel and finally you go back and re-measure at the same spot to see the relative change. This could give you insight into which damping/stiffening method is most effective, and that would be very useful info for sure.
Here's one available stateside. It's sold as an assessory for their ATB-pc SW, but I think it could be adaptable to some of the free SW out there.
Accelerometer
Accelerometer
The #MSP1001 and the ACH-01 are the same device (with various option for the wires/pins). They aren't tape-on pvdf's inside, they have an actual brass weight attached on top of a ceramic element, attached onto a one-side metalized ceramic mounting surface, with an FET buffer. I've had some apart (I used them in servo-feedback subwoofers, had the shielding paint inside the case come off - they get very sensitive to electric fields nearby when that happens!).
That Meniscus accelerometer looks an awful lot like an electret microphone!
That Meniscus accelerometer looks an awful lot like an electret microphone!
Depending on how much work you want to do, you could buy an Analog Out MEMS (Analog Devices has several, mouser or digikey), plumb it into your computer (line level) and do a sweep with REW or HOLM impulse or equivalent. Need low voltage power supply (maybe 2 AA batteries and buffer and done). Sparkfun might even have a breakout board.
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