060307 0343 - Luddite posted:

indago wrote:
I have an Amphenol Millivolt Commander Model 870, about 30 years old. It is
a sensitive, FET unit that uses batteries. Most of the batteries are
general AA 1.5 volt batteries (8), but 2 of the batteries are Duracell
Mercury 1.4 volt batteries (Duracell ZM9). I suppose that these batteries
are a reference voltage. Mercury batteries are no longer in use, so I used
two 1.5 volt batteries in their place.

When I turn the on and select battery test, the meter does not move. It is
supposed to move to above the Battery OK mark. Also, when I select the
positive DC, the meter pegs negative, and when I select the negative DC, the
meter pegs positive. The batteries are all new batteries, so there is not a
problem with dead batteries.

Anyone ever worked with one of these meters and can give me some insight
into the problem with it?


Polarity of mercury cells is reversed as I recall,turn the one pair
around if the holder will accept it.

All of the batteries are in their holders in the proper polarity, as shown
on the chart. I did change the two batteries as you had suggested, and
nothing changed with the operation of the meter.