If two different metals are in contact, a contact potential
results from the different electron affinity of the metals'
surfaces. The size of this potential is a function of the
temperature since the electron's kinetic energy increases with
These potentials also occur when the thermocouple is connected to a
voltmeter. However, they cancel each other (i.e., they do not
falsify the measuring results) if both leads which are connected to
the meter are of the same material.
A thermocouple consists of a pair of different metals, e.g. iron
and constantan. If the two contact points have different
temperatures, the difference between the contact potentials can be
measured as thermo potential.
- Real stand material for an esecially stable and safe setup
- Student-suitable experiment descriptions with reports available