HLab 12 (online). Calibrating a Hall Probe
HE1-A Hall Probe
Set of Helmholtz coils
Constant current supply
The Hall probe's output signal is a voltage that is proportional to the strength of the magnetic field in which the probe is placed. The calibration curve is a function that relates the Hall voltage to the strength of the field. Knowing the calibration curve, you will be able to use the probe to measure the strength of an arbitrary magnetic field. The two-axis Hall probe actually contains two probes oriented perpendicular to each other, so that the device can be used to measure two independent components of the magnetic field at a single location. You will determine separate calibration curves for each of the two probes.
In order to perform an absolute calibration of the device, you must put the probe in a known magnetic field. The best available source of a known magnetic field is a set of Helmholtz coils. This configuration is used to create a nearly constant magnetic field in the region around the point midway between the coils.
Work in a group of 2 or 3 people. All work must be done as a group. While you work, check each other out to make sure the probe is being positioned correctly and the meter is being read correctly. You'll enter some results online, so you'll need to have this page open on at least one computer while you're working. Enter all partners' names now.
Continuing Part B...