Mike did say to check them with a calibrator once you'd pre sorted them by =
resistance.=0D
=0D
Peter Shute=0D
=0D
Sent from my iPad=0D
=0D
On 06/04/2013, at 8:54 PM, "Raimund" <<r=
>> wrote:=0D
=0D
=0D
=0D
> Thanks for excellent input everyone!=0D
> I think I will go for the multimeter-solution.=0D
> I am currently on the EM172=B4s and getting the 470 ohm across the pad 1 =
and 3, with a variance of 2-3 (469-472)=0D
> So am I right that the capsules should be within 0.1 of eachother (f.ex 4=
Message: 70.
Subject: 1 and 470.2)? If so, I need a better multimeter.=0D
> Secondly, if this is right, am I right to assume one would be lucky to ge=
t a matched pair out of a batch of ten capsules?=0D
> Sorry for my lack of insight BTW, I=B4m working on it:-)=0D
=0D
Hi Anders,=0D
=0D
I think that John Hartog's approach is the way to go.=0D
=0D
I'm afraid that measuring the tiny differences of the 470 ohm source resist=
or does not help here at all. I'm pretty sure the 1% tolerance of the resis=
tor has nothing to do with the actual sensitivity differences of the capsul=
es.=0D
=0D
What instead matters are the specific tolerances of the internal FET transi=
stor (its gain), the electret foil and perhaps a few geometric tolerances w=
ithin the capsule. These much more relevant tolerances however cannot be me=
asured by a simple multimeter.=0D
=0D
Regards,=0D
Raimund=0D
=0D
=0D
=0D
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