If we measure the same situation with more mobile phones, we find out that
displayed data are different.
To create a noise map of the town, we need to use more mobile phones.
So we have to calibrate them.
In a big room, we put the best sound meter far enough from a speaker
and next to it we put a phone which we want to calibrate.
The microphones of both devices must be facing the same direction.
The calibration process:
- We will create a white noise.
- We will gradually set PC's volume so that the sound meter shows values
of 30, 40, 50, 60, 70, 80 dB
- We will note data from the sound meter into a table.
We will put the measured data into LoggerPro program and
we will examine which function is suitable for the description of dependance.
For our calibration is suitable the function y = ax+bx which has parameters a, b
X- data measured from a phone Y - real accurate data
For every phone it is important to make a table of measured data and
create a special calibrating equation.
In conclusion we will test given methods.
In a room we will create a sound of constant volume.
We will prepare 2 different phones and we will read shown data.
The phones have these calibrating equations:
We will input the measured data into calibrating equations and
there should appear almost the same results.
Is it difficult for you?
Try the simple, easy method.