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I have a mic having sensitivity chart as below which has relative dB on y-axis showing

1V/0.1Pa

what does this convey how to read my mic's sensitivity

a document on microphone sensitivity from analog says the microphone sensitivity is measure with 1Pa pressure as reference

confused in half way after seeing my datasheet of mic

enter image description here

usually i was of the opinion that the microphone sensitivity is measure with reference to 20micropascals,but i read with this SPL measurements so i am wrong

so if i have to buy an SPL i have to correlate my SPL with the microphone i am using

because if my microphone i am using in my application picks up some sound according to its sensitivity and the spl meter i am purchasing may not give me the required SPL level that i have detected

when i have seen the frequency Weighting curves of the SPL meter they are shown as below

enter image description here

what do these convey ? are they trying to attenuate some frequencies or they are trying to follow human auditory model

so if i have to buy an SPL meter having correlative sensitivity as of my microphone would be better,what is your opinion am i going the right way in selection of an SPL

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Microphones are typically specified in dB re 1 V/Pa. So am microphone with a sensitivity -44 dB (like this one http://www.panasonic.com/industrial/electronic-components/parametric-search.aspx?src=/www-cgi/jvcr13pz.cgi?E%2BSS%2B2%2BABA5010%2B0%2B4%2BAM) would produce 6.3mV RMS at 1 Pa of sound pressure. 1 Pa also corresponds to 94 dBSPL. So you can easily convert dB SPL in dB Pa by subtracting 94.

The datasheet for our microphone looks strange. I have never seen unit of 1.0V/0.1Pa before. This is potentially a print error.

The weighting curves do indeed mimic the frequency response of the human auditory system at different overall levels. However they are all 0 dB at 1 kHz, so if you calibrate at 1 kHz the weighting doesn't matter.

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  • $\begingroup$ if i consider the reference as correct then my sensitivity would become 39mV/Pa,if i consider this as a typo then 4mV/Pa but my microphone is so sensitive than the microphone you have shown me this is from knowless (FB30346) $\endgroup$ – kakeh Dec 20 '13 at 10:14
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The ref. unit mentioned is perfectly fine. Some microphone manufacturers use 1 dyne/cm^2. This would translate into -74 dB instead of -94 dB because the reference pressure applied is 0.1 Pa. So you can do the same math, just subtract -20 dB. To resume: to calculate the sensitivity you must: 20.*log10(sens.)-20. In you case, this would imply a sensitivity (sens. according to above notation) of about 40 mv/Pa, as you mentioned.

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