Do any of you record sound from your machines to include in reports? I often place the "horseshoe" of my hearing protection against a brg housing to hear what's going on inside, and would like others to be able to hear it as well. I am thinking that it would be a bit of data that would help the customer hear the change in the machine as well as see the change I show them with vibe data.

I was thinking a digital recorder and some kind of contact microphone. Are any of you doing this, and if so, what are you using?

Thanks in advance

DLI's ExpertAlert has provision for playing back sound, but I dont usually use it as part of my monitoring report.
Last year I had a problem with intermitant chirping noise from a pump that is not easily diagnosed using standard FFT processes. In that case, a wave file sent to pump vendor was more useful than an FFT that otherwise appears normal.

There are cautions to using sound files from software vendors- since they may be heterodyned and may not represent actual vibration. So use them appropriately (i.e. as marketing tool) to get your assessment across as necessary. Again, it all depends on how management/equipment owners usually respond to your monitoring reports.

I use digital recorders all the time, especially to post-process data at my desk.

Regards
Jim P

This is actually a common approach when utilizing hand held computers for your inspection rounds. Some systems will allow you to attach a wave file to the inspection point. This works great for intermittent sounds that appear under certain loads or conditions, or for demonstrating severity. Of corse you can always resort to ultra sound.

Michael,
I do this all the time with both ultrasound and vibration signals.
It is truly amazing how much more information you can get across by letting someone listen to a signal rather than look at its time signal or spectrum.
Best Regards,
Tom Murphy

How exactly are you capturing the sound files, Tom?

Michael, we discussed this at length some time ago (maybe on the old boards?). You might do a search.

I ocassionally use a PCB power supply with the 1, 10, 100 gain to directly recored the output of an accelerometer using a cheap digital recorder. Most such recorders auto-gain the mic input, so you sort of have to play with it a bit. You just need to make up a cable to go from the output of the power supply to the mic input on the digital recorder. Get a recorder that works with your PC and just download the recordings to your PC. They will be in a wav format.

I think it was on the old board.

Oli used to have a search engine for the old boards on his site.

If he still has it, I'm sure he will come around here soon.

Here was Rusty's thread on capturing vibration data as a sound file:
http://maintenanceforums.com/eve/forums/a/tpc/f/3751089011/m/4711076421/p/1

If you have saved a TWF in your database, you can always convert it to a wave file later. At least it's true in in E-monitor which allows you to export to exel. Once you've got the data numerically there are a number of tools available to convert it to wav... one method discussed on page 2 of thread linked above.

But it sounds like the reocrder method is easier if you're doing it on a routine basis and avoids sound anomalies that can occur when you try to splice/loop shorter wave files into a longer one.

And of course with the recorder there may also be the capbaility of capturing airborne sound data with a microphone. Seems like it could be handy on occasion. And more directly tied to what the customer (in our case Operations and Maintenance Department) hears when they are standing next to the machine.

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