DR ELDIN!!

How do you calculate sound pressure level?

Sound pressure level (SPL) calculator - formula & step by step calculation to measure the logarithmic RMS value of the sound or acoustic pressure caused by the sound wave relative to a reference value in decibels. SPL (dB) = 10 log10(p2/po2).

https://www.who.int/occupational_health/publications/noise1.pdf

https://www.mathworks.com/help/audio/ref/splmeter-system-object.html

Regards--

Have a look at https://au.mathworks.com/help/audio/ref/splmeter-system-object.html

https://books.google.com.au/books?id=qAWWn8oLoZUC&pg=PA131&lpg=PA131&dq=converting+pressure+signal++to+SPL-1/3+Octave&source=bl&ots=VRfSxZaBcF&sig=ACfU3U2RpBxfefuVzWiygT4BOnA-JiOtHQ&hl=en&sa=X&ved=2ahUKEwjCy7LlppXqAhVJyTgGHUUSB5cQ6AEwDnoECAkQAQ#v=onepage&q=converting%20pressure%20signal%20%20to%20SPL-1%2F3%20Octave&f=false

This may helpful for you.

https://www.mathworks.com/help/audio/ref/splmeter-system-object.html

First convert pressure sensor signal range between 0 to 5v...and calibrate with pressure using data sheet... Then apply convention formula

I used poctave function to convert pressure data (p) (time,pressure) to 1/3 octave spectrum

[P3rd, cf] = poctave(p,fs,'FrequencyLimits',[df,fs/2],'BandsPerOctave',3);

In order to calculate the SPL-1/3 Octave (sploct)

sploct = 10*log10(P3rd/pref^2);

Is the equation for calculating SPL-1/3 octave is correct or not?