I wonder how much this microphone is worth LOL :) For example how much would
> a comparable microphone cost ?!?
>
> Anyway I am hoping now that I can use this microphone to try and do some
> meaningfull measurements ?!
No, use a calibrated measure microphone.
I am not scared to do some arithmetic/math to convert whatever it takes to
> DB(A) or DB(C)... I might actually learn something from doing the math or
> so... and get a better understanding of it... and then maybe I will also be
> more sure that it's more or less correct for my purposes and law or so ;) :)
You may need some years to learn the basics, e.g. how to develop a FIR filter with many taps for the filter function.