Hello,
QuickDAQ does not have the ability to convert an mV signal from a microphone directly to dB.
I have a few notes about this and from what I picked up here and there this is how you get to dB.
First, determine sound pressure using the following formula.
Once you have sound pressure, use the following to get decibels:
Where P = pressure in pascals
Po = reference pascals (constant = 0.00002 Pa)
Let’s say the average value from the microphone is 10mV.
I’m going to use the Sensitivity value of 450mV/Pa (PCB.com p/n 378A04).
P = 0.010 / 0.450 = 0.022
dB = 20 Log( 0.022 / 0.00002) = 60.82dB
if you play with the numbers, 45dB is about 4mV.
I'm not a sound engineer so you should double-check this with the people at www.pcb.com.
