Did you ever get this corrected? I just found this thread looking for some other info on this meter and came across this. I guess better late than never. On the Mastersix meter, look at the top of the meter where the light enters the meter. There is a little slider switch there with 0 to 5 on it. If that switch gets moved over the +5 side all your readings will be off.
Sometimes when attaching accessories to the meter this switch gets moved.
Put it back to zero and all is well again.
Last edited by romanf; 02-09-2011 at 02:38 PM. Click to view previous post history.