[SI-LIST] Re: Sub .100 ohm measurements
- From: John Barnes <jrbarnes@xxxxxxxxx>
- To: codymiller@xxxxxxxxxx, emc-pstc@xxxxxxxx, si-list@xxxxxxxxxxxxx
- Date: Wed, 17 Jan 2007 13:32:06 -0500
Cody,
The traditional way to make low-resistance measurements is with a
4-Wire "Kelvin" measurement-- see
http://www.cirris.com/testing/resistance/fourwire.html
Quite a few of the medium- and higher-priced digital multimeters (DMM's)
have this capability.
On the GenRad 227X testers that we used to use at IBM Lexington/Lexmark
in the 1980's/1990'a, we could configure a 6-wire measurement that added
a drive wire and a sense wire for "guard" points. This was for
in-circuit measurement of resistors in configurations like
Rx
NODE1 -----o---------/\/\/\----------o------- NODE2
! !
! !
! Ry Rz !
+---/\/\/\---o---/\/\/\---+
NODE3
where Rx, Ry, and Rz were all low resistances. It's been over 16 years
since I last worked with the GenRads, and I no longer have the manuals,
so I don't recall the exact circuit configuration in the testers. But
we could measure shunt resistors in power-supply circuits down to about
the 50 milli-ohm range with about 3% accuracy in mass production.
John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, SM IEEE
dBi Corporation
http://www.dbicorporation.com/
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
- » [SI-LIST] Re: Sub .100 ohm measurements
