The Hall Probe
Depends on the Hall effect to produce a voltage that is proportional to a magnetic field,
thus allowing a measurement of the field
Only the component of the field perpendicular to the Hall sample is measured
Reversing the sense of the field will reverse the sense of the voltage measured →
The Hall probe can thus give a measurement of the direction of the field in addition to its
strength: the probe is rotated until the voltage reading is maximized; at this point, the
probe sample will be perpendicular to the field.
The sense of the voltage will tell you which way the field goes.
A solenoid is a long coil of wire. The length of the solenoid must be much greater than
the diameter. In addition, the dist