Electricity and Magnetism > EMF and Current
 DCS# 5E50.19
THERMOELECTRIC COMPASS

APPARATUS
thermoelectric compass 202-11-E6
loop with binding posts
 202-11-E6
butane burner
 202-11-A
beaker of cold water
 101-01-C
power supply
 202-08-E
ammeter
 214-01-B6

DESCRIPTION
Start with the loop parallel to the compass needle.  Cool the bottom tab in cold water and heat the upper tab in the flame of the burner.  The deflection of the magnetic needle is an indication of the size and direction of the current produced by the thermocouple.

The second loop with binding posts can be connected to a power supply and ammeter to measure the current necessary to produce an equal deflection of the magnet.
NOTES
 
The compass needle is surrounced by a copper strip, with a bridge of copper-nickel alloy silver-soldered across the ends.

Use the 10 A scale of the ammeter.