Review on Automated Scientific Teaching Magnetic Field Detector by Eddie Gordon

As advertised, these viewers (compared to others I've looked at) offer a slightly easier interpretation of analog field strength readings with really sharp gradients. Seems to have no memory/residual charge so degaussing doesn't seem necessary. They are mounted on some sort of sturdy cardboard with a 3/4 inch bezel all around to prevent the viewer from presumably coming into direct contact with the magnets being viewed. to protect the active bottom from damage, and it definitely looks like there is also an inactive protective layer on top. This design may not allow you to directly visualize the proportions of the field relative to the object under study, as you can with a translucent viewers would do, but this is a minor inconvenience far from outweighed by the superior aesthetics of a colorful image. I removed the box from two of my units and installed them on a 10 mil FR4 with double sided PSA. They are surprisingly tough as I had to take one off to release a few air bubbles which I caught. The underside is pitch black. Overall, this is well thought-out magnet technology.