---
# System prepended metadata

title: REPORT ON RELATIVE CALIBRATION OF THE MICROPHONES

---

# REPORT ON RELATIVE CALIBRATION OF THE MICROPHONES 

## RESULTS OBTAINED

* We have done three cases for the relative calibration i.e, three types of signals were given to the speaker 
    - sine wave with amplitude 2mV, frequency 200Hz and time 100sec
    - chirp signal with amplitude 1mV, frequency from 250Hz-2500Hz and time 100sec
    - chirp signal with amplitude 2mV, frequency from 250Hz-2500Hz and time 100sec
    
### sine wave with amplitude 2mV, frequency 200Hz and time of 100sec

* the pressure time series data of the 5 microphones which includes absolutely calibrated microphone is shown below

 ![](https://i.imgur.com/2oOqnip.jpg)


* the pressure time series data of the five microphones with time shown upto 1sec in the box.
 
![](https://i.imgur.com/LkZjZCb.jpg)

 
* the pressure time series data of the five microphones with time shown upto 5sec in the box.

 ![](https://i.imgur.com/BjjiEnX.jpg)
 
* the pressure frequency domain of the five microphones is shown below 

 ![](https://i.imgur.com/vKKHp8Z.jpg)

* the detailed view of pressure frequency domain for the five microphones is shown below 

![](https://i.imgur.com/j9QNeuo.jpg)

  
* rms value of pressures of the microphones are shown below

     | rms value of the pressure   | value |
     | -----------                 | ----------- |
     | rms voltage of input signal | $\sqrt2$ mV
     | absolutely calibrated       | $5.0945$ Pa   |
     | microphone 1                | $4.3759$ Pa|
     | microphone 2                | $3.8967$ Pa            |
     | microphone 3                | $6.2414$ Pa           |
     | microphone 4                | $4.2038$ Pa           |

### chirp signal with amplitude 1mV, frequency from 250Hz-2500Hz and time 100sec

* the pressure time series data of the 5 microphones which includes absolutely calibrated microphone is shown below

![](https://i.imgur.com/QwSROm5.jpg)

* the pressure time series data of the five microphones with time shown upto 1sec in the box

![](https://i.imgur.com/uKKZkiw.jpg)

* the pressure time series data of the five microphones with time shown upto 5sec in the box

![](https://i.imgur.com/92mVwKB.jpg)

* the pressure frequency domain of the five microphones is shown below 

![](https://i.imgur.com/IM8wX9E.jpg)

* the detailed view of pressure frequency domain for the five microphones is shown below 

![](https://i.imgur.com/l6ilFaB.jpg)



* rms value of pressures of the microphones are shown below

     | rms value of the pressure   | value |
     | -----------                 | ----------- |
     | rms voltage of input signal | $0.7053$ mV
     | absolutely calibrated       | $2.4462$ Pa   |
     | microphone 1                | $2.7339$ Pa|
     | microphone 2                | $2.7433$ Pa            |
     | microphone 3                | $3.0999$ Pa           |
     | microphone 4                | $3.2027$ Pa           |

### chirp signal with amplitude 2mV, frequency from 250Hz-2500Hz and time 100sec

* the pressure time series data of the 5 microphones which includes absolutely calibrated microphone is shown below

![](https://i.imgur.com/nEEa8Dg.jpg)

* the pressure time series data of the five microphones with time shown upto 1sec in the box

![](https://i.imgur.com/PE6JD94.jpg)

* the pressure time series data of the five microphones with time shown upto 5sec in the box

![](https://i.imgur.com/aUUJgn5.jpg)


* the pressure frequency domain of the five microphones is shown below 

![](https://i.imgur.com/pls7b86.jpg)

* the detailed view of pressure frequency domain for the five microphones is shown below 

![](https://i.imgur.com/0vCaFGI.jpg)


* rms value of pressures of the microphones are shown below

     | rms value of the pressure   | value |
     | -----------                 | ----------- |
     | rms voltage of input signal | $\sqrt2$ mV
     | absolutely calibrated       | $3.1395$ Pa   |
     | microphone 1                | $3.5455$ Pa|
     | microphone 2                | $3.5019$ Pa            |
     | microphone 3                | $3.6339$ Pa           |
     | microphone 4                | $3.9622$ Pa           |


  





