Vanny1666
Jun 21, 2007, 03:27 PM
Instrument which measure the Earth's magnetic field are called
Capuchin
Jun 21, 2007, 10:20 PM
Compass (http://en.wikipedia.org/wiki/Compass), Magnetometer (http://en.wikipedia.org/wiki/Magnetometer), Hall Device (http://en.wikipedia.org/wiki/Hall_effect#Hall_effect_in_Semiconductors).