At 07:53 PM 6/13/2006, Olin wrote:
>Rich Graziano wrote:
> > Yes they are related, but the EMF
> > produced by the junction is a thermocouple effect.
>
>Once again, it's not the junction that produces the EMF.

It's disingenuous to say it's not the junction that produces the EMF.

Of course, it takes a temperature difference between two junctions to get 
an EMF. But it is also true that every other junction at a different 
temperature will also contribute to the EMF. That's why it's important to 
know where the junctions are, and what temperatures are being measured.

Thermocouples have the failure mode of including extraneous junctions due 
to wire stress or breaks at intermediate points. So the wires have to be 
maintained and discarded periodically.

It is also true that all junctions at the same temperature sum to zero EMF 
between them.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral@lcfltd.com
Least Cost Formulations, Ltd.            URL: http://lcfltd.com/
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Virginia Beach, VA 23464-3239            Fax: 757-467-2947

"Vere scire est per causas scire"
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