Real-Time Measurement and Control

cancel
Showing results for 
Search instead for 
Did you mean: 

Microphone performance

Solved!
Go to solution

Hello

 

I am acquiring unknown sound data for research purposes. I want to make a random check if my microphone is measuring correctly. I have a sound meter that measures SPL in dB. I am not sure how to convert the data I got from the microphone to a sound pressure level (SPL) in dB. The question here is not about the formula to compute SPL (dB) in Pa. My main question is about the relationship between the data acquired and a sound in Pascal (Pa).

Considering the data is in mV, I tried to multiply and divide it at a time by the microphone's sensitivity (in mV/Pa) to compute the SPL (dB in Pa) but the value I am getting does not seem right. I took 0.00002 Pa as a reference.

 

My data acquisition system comprises the following

  1. Model: 130A23 | ICP® Electret Array Microphone and
  2. NI9234: 4-Channel, 51.2 kS/s/channel, ±5 V, C Series Sound and Vibration Input Module

Looking forward to your help on how to resolve this issue.

Many thanks for your time.

Jaefer

0 Kudos
Message 1 of 3
(158 Views)
Solution
Accepted by topic author Jaty22

Use this technique,

  • Capture mic waveform
  • Scale the waveform by mic sensitivity
  • Compute RMS
  • Calculate 20log(rms/20u)
  • Now you've dB SPL

If you could share some sample data and mic sensitivity, one can calculate these

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.
0 Kudos
Message 2 of 3
(135 Views)

Thanks Santhosh.

0 Kudos
Message 3 of 3
(101 Views)