Very often a SID observer will want to build a magnetometer to complement the SID method of monitoring for solar X-ray flare events. These events and the solar CME events that sometimes accompany them will often produce a more direct effect here on earth. These are geomagnetic disturbances where the particles and magnetic fields ejected from the sun impinge onto the earth's magnetosphere resulting in a geomagnetic storm. The AAVSO SID program does not track this activity but observers enjoy detecting the activity on the sun and the resultant effects here on earth. To do this they use a magnetometer that detects the changing strength of the Earth's magnetic fields when the effects of a SID producing flare/cme event arrives here at the Earth. The following links are to magnetometer related articles that have appeared in past issues of the Solar Bulletin. They were all authored or edited by past SID Technical Coordinator Cap Hossfield. There are other references available on the web if you search on magnetometers but these here will provide an overview of what is possible.

FluxGate Magnetometer
FluxGate Magnetometer Integrator
Permalloy Strips in Magnetometer
Rebecca's Magnetometer
Torsion Balance Magnetometer
ED Los Magnetometer