01/20/2019: The Original Hall Experiment

A project log for Making Sense of the Hall Sense

The Physics Behind The Hall Effect Sensor

TheRealDubzTheRealDubz 01/21/2019 at 04:520 Comments

Doing some more research, I found that I'm basically re-creating the 1879 E. Hall experiment.  It's a very interesting read, and relatively easy one too due to it being written in the first-person narrative.  Papers these days are so dry and boring :).    

Hall stated the strength of the magnetic field he used was 20,000 times the strength of the "horizontal intensity of the earth's magnetism."  According to Wikipedia, Earth's magnetic field at the surface ranges from 25 to 65 microTeslas.  So let's see what it would take to generate 0.5 to 1.3 Tesla.

Another thing to notice about the original Hall experiment is the magnitude of input current that was put through the gold leaf.  From the looks of the data, the current put through the gold leaf was less than 100mA.  The test data Hall had collected did not have clearly defined units in the table, see below:

Hall goes on to postulate that the E-field generated is related to the momentum of the charge carriers (mass x velocity of charge carriers), with the velocity of electrons being equivocated to "C/s."  However, "C/s" in his paper means the ratio of input current to cross-sectional area of the hall element (which is actually current density).