Experimenting with Thermocouples.

... Physics AS Level Coursework Experimenting with Thermocouples Introduction For my sensor coursework, I have chosen to investigate the properties of thermocouples. A thermocouple is a sensor which detects a temperature difference, and produces a very small electrical output. "In 1822, an Estonian physician named Thomas Seebeck discovered (accidentally) that the junction between two metals generates a voltage which is a function of temperature. Thermocouples rely on this Seebeck effect. Although almost any two types of metal can be used to make a thermocouple, a number of standard types are used because they possess predictable output voltages and large temperature gradients." Source: http://www.picotech.com/applications/thermocouple.html Welding, or otherwise combining, two dissimilar metals can make a thermocouple. Varying the temperature of the junction where the two metals combine will produce a very small voltage and a very small current. However, if one attempts to connect the thermocouple to a Voltmeter, another thermocouple junction is made. This is at the point

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