Magnetometer

Amateur Magnetometer

Following instructions from a the Society for Amateur Scientists (www.sas.org, www.scifair.org), an inexpensive torsion magnetometer was built. It uses a rare earth magnet hanging by a thread of nylon, shown below. (Great additional pictures and information here for the kit.)

Above: laser pointer in the foreground. Magnetometer in middle. Upper right: four donut-shaped secondary magnets are used to null out the earth's magnetic field.

The laser pointer's reflection off the magnet is aimed at a wall. And a webcam is aimed at the laser spot on the wall.

A Windows program was written to capture the webcam's video and to chart the movement of the spot in real-time. The program is available for free from this link as an exe or this link as a zip file.

Note that Microsoft's (free) DirectX version 9.x or greater is required for this program to run! Check your current version by running dxdiag.exe, which should be in c:\windows\system32. Most newer computers will have this already installed. You can download the latest from Microsoft at this link.

If you use the program, please, please email me to tell me your results. Click on the link below to send me e-mail. Send me a photograph of your science project (and hopefully of your first place award!), or send me a link to your website if you've got one. I'll post it here on the web (with your permission), or I'll email back to you a link to download special access code that unlocks more features in LaserTrack!

I'm happy to answer questions about the program or building your magnetometer. And don't forget that if you're a member, you can also get questions answered www.sas.org.

Here's what the program looks like when it's running:

To see a short Macromedia video on how the program operates, click here. (Be patient. It stalls for about 15 seconds shortly after it begins playing)

Below is USGS data (from here) compared to my data. I'm delighted at the similarities!

Below is a different plot from the USGS that I used to calibrate my graph.

This file is a pdf with a presenation I presented to the Seattle Astronomical Society ppshow.pdf

Below are two neat NASA animations showing how the sun influences our magnetsphere.
You click to play them here, or right click to save them to your desktop so you can play them full screen! (Use CTRL-Enter while viewing them off-line in the Windows Media Player!)

Animation 1 - Shows how we currently think a sunspot (with a magnet North and South pole) is created and in some circumstances, can cause the ejection of material.

Animation 2 - Shows how charged particles from the sun influence the Earth's magnetic field, resulting Aurora (the "Northern Lights") as well as fluctuations on your magnetometer!

Dear Amateur Scientist,
To create the LaserTrack program, and maintain this website takes time. The program is yours to use, free of charge. (Don't post it anywhere on the web, please.)

If you found this program helpful to you or your budding-scientist child, perhaps you'll show your appreciation by making a small donation to keep the program improving? If you're under 21, then discuss this with your parents. Surely they'll want to demonstrate to you right attitude in giving back to people who help you.

Sure all of us rip MP3s from the web. But, this is different. I believe in "pay it forward" (and amateur science) which is why I'm giving you the program for free. But I'm also personally asking you to "pay it forward." Remember, "What goes around comes around." Like you, I'm a real person. I live in Seattle, Washington and I watch either Jon Stewart, South Park, or Fox News ... whichever one you watch!

You can click on the link below to use PayPal to make a safe donation. Or click on my mail link further up this page and send me a quick thank you!