Not sure if I should post this in here, or in the Ultrasonic Section...

Does anyone have experience collecting noise data with their vibration equipment? I have a dataPAC 1500 and we just got a TMS 130P10 microphone for it. I have the setup sheet from ENTEK, but the numbers I'm getting don't jive with what our other BK audio meters are reading. For instance, in my office I'm reading almost 100 dBA. In reality it's only about 83 dBA.

Any thoughts? Thanks.

Bill,

Wow, you really have a noisy office! Most offices are below 65 dBA. I don't know the datapac, but I guess that you are using the wrong sensitivity. Here are some related comments:
http://maintenanceforums.com/eve/forums/a/tpc/f/3751089...001031023#4001031023

Walt

My office sits right above 4 large (200 HP) IR Recip compressors... Let's just say, noise is only one of my issues!!

The paper work that came with the microphone says it's calibrated at 25 mV/Unit. And that's what I have the dataPAC set too...

Bill,

The nominal sensitivity of the microphone and ICP preamp is 45 mv/Pa or 0.045 Volt/Pa. The difference in sound levels was 17 dB between your B&K sound meter and the DataPac with the ICP microphone. Based on the fact that there is a lot of low frequency sound in your office from the recip compressors, my guess is that your B&K meter is set to measure A-weighted dB or dBA while the DataPac is probabaly measuring unweighted (Linear) dB level. You could verify this by setting the B&K meter to Linear (unweighted) or C-weighting and see if it reads closer to the DataPac. I know the CSI analyzer can do A-weighting, but I don't know about the DataPac. If you really need A-weighted sound spectra, and the DataPac can't do it, then you have two choices: purchase an in-line A-weighting filter to attach to your ICP preamp, or connect the AC output from the B&K meter and use its A-filter.

Walt

Bill,

Have you resolved your sound measurement discrepancy yet?

Walt

Walt and Bill,

The DP1500 will do either A,B, or C weighting in sound db.

Dave

I have written a procedure and can post it next week. I use an ACO Pacific ICP powered mic, it might be the same. Do you have a calibrator? If you don't you need to get one.