Pico TC08 USB THERMOELEMENT DATA LOGGER PP222 User Manual

A discovery by T. J. Seebeck almost 150 years ago opened the way for modern thermoelectric
circuitry. In 1831, Seebeck discovered that an electric current flows in a closed circuit of two dissimilar
metals when one of the two junctions is heated with respect to the other.

In such a thermocouple circuit the current continues to flow as long as the two junctions are at different
temperatures. The magnitude and direction of the current is a function of the temperature difference
between the junctions and of the thermal properties of the metals used in the circuit. This phenomenon
is known as the Seebeck Effect.

The conductors can be made of any two dissimilar metals, and when the hot junction is heated the
current flow can be observed. If the position of the hot and cold junction is reversed, current will flow in
the opposite direction.

In fact, a thermocouple circuit will actually generate a measurable, low voltage output that is almost
directly proportional to the temperature difference between the hot junction and the cold junction. A unit
change in this temperature difference produces some net change in the voltage.

Note: More information on choosing and using thermocouples can be found 

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