John,
Thanks very much for the info...I think.
Looks like the one I've got should be used for testing the coffee pot, or maybe the hair on the neighbors dog's back.
It's already helped me to find a hot connection on an energized xfrmr, and although not totally accurate, I'll still be able to make comparative tests. (About $100, 8-1 ratio,etc).
$20K is more than my company truck's worth!