Measuring Local Variances in Earth’s Magnetic Field
1 min read
Summary
While generally reliable, the Earth’s magnetic field has slight variances in strength around the planet, which is noticeable when measuring with a compass and another magnet.
As the original article explains, by noting the deflection of the compass needle when a known strength magnet is placed near it, the strength of the Earth’s magnetic field can be worked out.
However, the comment chain asks how to measure the starter magnet’s field, and whether the method of using another magnet makes it harder to get an absolute reading for the Earth’s field.
One reply suggests using Helmholtz coils along with a sensitive multimeter to get an accurate reading of the Earth’s absolute magnetic field strength.
Another commenter suggests using the torque exerted on a pivoted magnet in a bell jar to measure the strength, which they say they’ll try with their 10th-grade physics class.
