wrote in message
...
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.

I'll bet that you clamped the current jaws around a 2 or 3 conductor cord,
right? If so, your meter will read zero all day, no mater how much current
you have in the wires. Oh, and it must be AC current; it won't work on DC.
The reason that the meter won't work if clamped around both conductors in
the cord is that the fields created by the current cancel each other.
You'll have to split the cord so that the clamp only has one of the
conductors inside. Then, it should work as advertised (assuming that
nothing is defective in the meter).
I recommend the line splitter at
http://www.licensedelectrician.com/Store/AM/ELS2A.htm. It will allow you to
check current on an appliance without having to split the cord open to
isolate the conductors.

You can download a copy of the manual for your meter from
http://www.amprobe.com/manuals/RS3.pdf

Cheers!!! Great find!!!
--
Dave M
masondg44 at comcast dot net

One good thing about Alzheimer's; you get to meet new people every day.