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Can anyone give the exact circuit analysis of a bridge circuit in which 3 wire and 4 wire RTDs are connected, and how the terminal wire resistance gets cancelled?

http://www.rdfcorp.com/anotes/pa-rtd/pa-rtd_04.shtml

or this one

http://newton.ex.ac.uk/teaching/CDHW/Sensors/an046.pdf
< br>Steve
www.mtl-inst.com

Sreeraj,
If you are familar with a Wheatstone Bridge. The 3 wire RTD is placed in the circuit with one wire in one leg and one wire in the other so the added resitance of the leads, terminals etc. effects both sides of the bridge to the same degree. The third wire is in the potential meaturing circuit so it's resistance has no effect. If you send me your e-mail I will send a sketch. rmatson@noram-eng.com

Roy