how to get correct FFT (dB), since the microphone measured volts?

[128]

Dear Friends:

I am using microphone to measure a signal.  It provides me the data in the unit of volts.  you know i want to do FFT to get the Sound Pressure Level in the unit of dB.

Does anybody have any idea how to make volts to convert to pa, so that i can calculate the sound pressure level in dB?

Many Thanks

Cheers

Dan

[Sarah_Coleman_NIUK]

Hi Dan,

The following tutorial lists the formula you need to convert your voltage measurement to Pa.

Regards,

[128]

Hi Sarah:

thank you so much.

cheers

dan

[BK Lian]

Hi Sarah/Dan,

Are you refering to Pressure = (Cfs/Vex)(Vmeas/CF)?

P.S. I'm using the NI Speedy-33 board and do you know how to get the parameter(s) for it?

Thanks in-advance!