At 11:32 AM 4/22/99 -0700, Chuck McManis wrote:
Somewhere in my boxes of stuff I've got one of
the tape "visualizer" cards.
Its looks like a translucent grey plastic card and when you hold it over a
magnetized surface it shows the magnetic "spots" by turning white (what it
There's also the $9-$20 "Magnadoodle" technology available in the toy
section of almost any store that flips from white to black after
having been exposed to a magnetic pole. I thought you had kids. :-)
I have a spray can of stuff that is used to make analytical measurements on
magnetic media. Spray it on, and you can see the tracks and transistions
with a microscope.