From: No  Spam 
Newsgroups: misc.consumers.house
Subject: testing gas furnace pilot thermocouple
Date: Thu, 20 Nov 2003 19:06:13 GMT

I thought I had a defective thermocouple because the pilot wouldn't stay 
on after releasing the "start" button.  I was told a working 
thermocouple put out 300 mV.  Mine measured 30 mV.  So I tested a 
friends functioning thermocouple: 30 mV.   Hmmmm...

I was measuring with a high impedance meter from the center of the 
button that screws into the gas control to the outside of the copper 
conductor (near the button).  Does the thermocouple actually develop a 
measurable voltage?  

My problem disappeared when I screwed the button back into the gas 
control.  A little experimentation revealed the control is very 
sensitive to a loose connection.  Yet for future reference, I wonder if 
it is possible to test a thermocouple without just swapping in a new one.

Thanks