(Instructions were not included)

I asked Annis but they were not at all helpful and pointed me to their
site where I didn't find the specifics on how to actually use it to
test for tape path magnetism.

If you could spare a few moments of your time help me out that'd be
great!

Thanks!

How about these instructions on thier website?

http://www.maginst.com/Annis%20Pocke...etometers.html