A Hall probe is a sophisticated instrument used to measure magnetic field strength. It is a thin film that measures the transverse voltage when it is placed in the magnetic field. The Hall probe works on the Hall effect that was discovered by the scientist E.H. Hall in 1879.
The measurement of large magnetic fields on the order of Tesla is often done by the Hall probe, as claimed by Hyperphysics, a website hosted by the Department of Physics and Astronomy at Georgia State University.
Hall probe is a metal strip carrying electric current from left to right, as stated in Scientific American. This probe works as follows:
- A magnetic field is applied perpendicular to the electric current flowing through the Hall probe. As a result, the current carrying charged particles no longer move from left to right of the probe.
- The positive charges are pushed upwards while the negative charges are pushed downwards. Thus, a measurable potential called Hall potential is developed between the two ends of the probe.
- Any change in magnetic field produces a corresponding change in Hall potential, which is detected by the Hall probe. The probe can detect slow and small fluctuations in the magnetic field. It has high accuracy of hundredth of a gauss.