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How can I use the built-in Sound and Vibration VIs with prepolarized microphones

I am programming an application for a customer who uses prepolarized microphones. They have a G.R.A.S. 12AR conditioner to provide the power to the mics, and a NI 9239 for acquisition. When I attempt to configure a channel as a microphone, the built-in VIs all expect a DSA board with IEPE excitation - I believe this is unnecessary. How can I configure this channel as a microphone and still use the built-in applications without huge modifications?
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Unfortunately, your hardware won't support a plug-and-play Sound Pressure task, and it would require that you use a DSA module like the 9234. Your best bet is to take in raw voltage readings with an analog input task and convert those voltages to dB or whatever scale you wish to use. What scale do you need your data to be read as?

Mathew H.
Applications Engineer
National Instruments
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Matthew,

 

Thanks for the reply.  Other than the lack of IEPE and AC coupling built-in, are there any other reasons why it would not be possible to use the 9239?  There are legitimate reasons why I specified the 9239 for this project, and the IEPE and AC coupling are unnecessary with my setup.  Would NI consider creating a Sound Pressure task that does not require a DSA board, when prepolarized mics are used?

 

I need to scale to dB Re 1 pW.

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The control over IEPE are the reason for these types of DSA tasks, or else it would just be an analog input channel with scaling. Therefore, an Analog Input task is effectly the same task as a Sound Pressure task without control over IEPE and AC coupling.

Mathew H.
Applications Engineer
National Instruments
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