To be "Kelvined" means to use one pair of leads to supply the current and another pair of leads to sense the voltage. Google "Kelvin four point probe" and you will find several articles. This looked pretty good when I gave it a quick scan. Two-Point and Four-Point Methods for Measuring Small Resistances The four-point resistance measurement method eliminates lead resistance or ... Special connecting clips called Kelvin clips are made to facilitate this kind ... www.sciencebuddies.org/mentoring/project_ideas/Elec_p025.shtml?from=3DHom= e -=20 Aubrey Sparkman=20 Enterprise Engineering Signal Integrity Team Dell, Inc.=20 Aubrey_Sparkman@xxxxxxxx=20 (512) 723-3592 The Greatest Pleasure in Life is Doing what People say can't be done... -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Taylor Jones Sent: Wednesday, August 23, 2006 2:42 PM To: si-list Subject: [SI-LIST] Re: DC resistance measurement On 8/22/06, Andrew Ingraham <a.ingraham@xxxxxxxx> wrote: > > Accurate DC resistance measurements sometimes require a "kelvin" or=20 > 4-lead connection ... two leads to pass current through the device,=20 > and two > *separate* leads for measuring the resulting voltage drop. That way,=20 > I*R voltage drop across the connection points, leads, etc. is negated. This brings up a term for which I was looking for more information, but couldn't find anything. I have an AppNote that says: The traces to and from the FET's source and the VDDEXT supply pin on the Blackfin processor should, if possible, be Kelvined to their power supply to avoid transient effects on other devices connected to the same supply. What exactly does it mean to be "Kelvined" to their power supply? ~ Taylor Regards, > Andy > > > Now, we are measure DC resistance of power plane in PCB. The=20 > > presision should be 0.1 mohm at least. However, because of the clamp > > of the meter, the error is about 1m ohm. In another word, the=20 > > difference between two measurement for the same DUT is about 1 mohm. > > Is there any advice about this topic? Anything will be help. In your > > measurement, how to connect > the > > probe to the plane? > > ------------------------------------------------------------------ > 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 FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > 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 > > > ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =20 //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 =20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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