configure a microphone on PXI4472

[anaga2]

I have a PXI4472 board and I want perform a noise acquisition of some equipments.

To make that I must use 5 microphone.

Before buy more expensive microphone, I need know how I can configure a normal microphone with this board.

The microphone that I have, has the following characteristics:

Type:Moving coil dynamic

Frequency response: 40Hz - 16000Hz

Sensitivity: -72dB (0dB = 1V/microbar at 1000Hz)

Output impedance: 250 Ohm

Please tell me how I must configure the board to use this type of microphone and please tell me how I can converse the voltage measurement of the board in noise decibel.

Best Reagrds

Andrea

[Filippo_Persia]

Hi Andrea,

In order to configure your board you have to use Measurement & Automation Explorer ( MAX ).
This tool allows you to set up the board and instruct the drivers about your microphones specifications.

Starting MAX follow these steps:
Right Clik on Data neighborhood>>New Task>>Analog>>Sound Pressure>>select your physical channel for instance ai0 on 4472 >>name the task>>press finish.

You should be able to get quite easily to the configuration panel ( see figure ).

Here you can instruct the board on how your microphone works.
To configure your microphone you must find out the right specifications, important data are about power supply and microphone sensitivity.
If you need you can supply power to your microphone as long as it's IEPE compliant.
You can find more information about this feature and dig further on how work properly your DSA in the 4472 manual.

If you need to transform Pascal values to dB you can use the following formula,

SPL = 20 log10 (p/pref)

where p is the instantaneous sound pressure in Pa and pref is 20 µPa, the internationally accepted reference for sound pressure measurements, which roughly corresponds to the threshold of human hearing.

It's the same suggested by MAX in the rightmost tab.

Hope you can start working easily now.

Best Regards