Originally Posted by Anechoic
As the graphic lennon_68 pointed out, there really isn't a "typical" correction curve, there is a pretty wide unit-to-unit variation.
In terms of sending it out to some place more local to you, have you looked into these guys
I noticed they were listed on your page as a source for calibration.
However, sending it out (and back) for calibration to germany is like buying a brand new one, so what I am actually considering is buying a second measurement mic, calibrated, from them, and use the ECM8000 I have as a spare. I could then also easily correlate the two mics, to get a "decent" cal file for the ECM8000 I have...