Now I got how did you acquire 5 stars on your name.

I have openly admitted that the star rating represents only quantity; not quality:
http://www.8052.com/forum/read.phtml?id=24265

"Tell me honestly the amount of HELP in your reply???"

OK: the amount of specific help was to confirm that you have correctly identified the required transducer; viz, a microphone

In addition to this, I pointed out to you that SPL meters are calibrated according to various weighting scales; maybe you did know this already, but you did not mention it. Therefore I mentioned it incase you, or anyone else who reads this thread, might have overlooked it