Thermocouples generate power based on a temperature difference between the cold junction and the hot junction. If both are at the same temperature, no voltage. You might look at it as the two junctions generating voltages of opposite polarity that are in series, so you could TRY to have just one junction. But, it appears when you wire the circuit together, you always have two junctions. Harold -- FCC Rules Updated Daily at http://www.hallikainen.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist