is there an example problem for calculating absorption coeff. ?

[zq]

I needed to create a labview program to calculate the absorption coefficients for foam samples from impedance tube.

What I needed to do is to create white noise for the speaker, read in the pressures from two microphone averaged for

15 seconds, and calculate the absorption coefficient. I suspect this to be very common and wanted to find out if there

is an example on something similar.  Thanks, Zakir (734) 779 7125 office

[Minh T.]

Good morning Zakir,

Sounds like your application is ideally suited to our Sound and Vibration Toolkit:

https://www.ni.com/en-us/shop/product/labview-sound-and-vibration-toolkit.html

You can have a look at the User Manual to see its full capabilities:

https://www.ni.com/docs/en-US/bundle/labview-sound-and-vibration-toolkit/page/svmain/svmain.html

There is an example program that ships with the Sound and Vibration Toolkit called the SVXMP_Sound Level Meter (DAQmx).vi which would be ideal for reading and averaging SPLs from a microphone with a wide variety of parameters such as averaging time constants, weighting, filtering and so forth.  Using this in conjunction with a DAQmx analog output of white noise and you should be set.

If you don't already have a device to perform this test, a great option would be the PXI-4461, one of our Dynamic Signal Analysis cards:

https://www.ni.com/en-us/shop/model/pxi-4461.html

It has 24-bit resolution, 2-inputs and 2-outputs and can sample/update at 204.8 kS/s.

Best of luck with your project, please let me know if you have any further questions.

Sincerely,

Minh Tran

Applications Engineering

National Instruments

[yuvi1990]

Dear zahir,

Me also doing same thing now.i have constructed impedance tube if you share vi means useful to me . 

E-mail: mechanicalyuva5236@gmail.com

[Nando03]

hey yuvi...

can you help me? i need program to measure sound absorption coefficient in labview.. i will make sample with fly ash. 

thanks..