I picked up this probe at a yard sale for 5.00. After cleaning up the
connectors and installing a new AAA battery it works on resistance and
voltage ranges with the accessory cables supplied but when clamped
around a current carrying conductor it reads zero. I'm guessing that
there must be some kind of coil wrapped around the jaws internally on
this thing in some way. Current flowing through a conductor would
induce a voltage into this "primary" with a "secondary" connected to
the meter. I'm guessing here. I'm not really sure what is inside of
this meter. Can anyone tell me something about the theory of this type
of instrument and if they have any experience with this model. I may
have to get inside and would really appreciate some help with that as
well. There doesn't seem to be an easy way to do that without a
special tool. The company was no help at all.Thanks, Lenny.