3.5 DIGIT LCD PANEL METER, 0.2V SCALE

The documentation sucks. I've used about 100 of these meters in an application that requires read out of seconds of run duration and of grams of chemical flow per minute. I power a pair of the 200 mv model meters off a standard 12V 3-pin plus regulator with 100 mf of electrolytic cap filtering the requlator output (no ceramic bypassing), and they are very stable, acurate, and trouble free. The same PS also powers four NE-555 timers and several relays. A free floating 3V wall wart transformer supplys the measured voltage.

I made up a PC board with calibration pots to suit my application and use a standard 14-pin ladder type dip socket cut right down the middle with diagonal cutters. The meters plug right into the cut-down-the middle half dip sockets. One socket split down the middle and soldered to two different places on the meter board provides the plug in sockets for two meters.

Alternatively, one can just quick and dirty solder wires to the pins of a split-down-the- middle 14-pin dip socket, and plug the half socket into the meter. It's probably a bad idea to try to solder directly to the meter pins.

This little meter provides a lot of reliability and precision for the buck. The snap in feature is pretty crude and sloppy. Once snapped into a precision tight fit hole in a 0.060 sheet metal panel, the meters are very tricky to remove. I settled on a rectangular hole 2.225" wide x 1.490" high. That's slightly sloppy, but it allows removal without destruction. RTV can cure the sloppyness, but why bother? If a LCD segment fails, or the meter loses precision, it should be easy to snap in another meter.

After reading the comments about the isolated supply, I used a single 9V battery. The instructions say 50-60 mW, but I measured less than 1 mA into mine. A 9V alkaline battery will power it for 500+ hours at that current. I turn the meter off when I am not using it.
I strongly advise against powering two meters from one battery. I suspect that is the source of the problems cited in the other comments. Two PM-200s connected together at the supply probably makes a path between the measured voltages in each, resulting in catastrophic failure.
I monitor (but not at the same time) with one PM-200 a 2 amp current with a 0.1 ohm shunt and a 20VDC voltage with a 100:1 divider built of a 1.00meg series resistor, and 10.0K and 200. ohm resistors in parallel to ground. Without adjustments, this agrees with my Fluke within the last signficant digit.
The PM-200 was not design to mount in a sheet metal panel. I cut the hole exactly as specified. The meter went in fine, but rattled around. I secured it in place wiith four small drops of RTV.
The readout contrast is excellent. It looks good in my power supply.

In answer to the previous question, the 8-pin connectors at each end of the small cable CON-88 will work with this meter and others like it. The meter requires four connections with 0.2" spacing, so cutting alternate wires at each connector will provide two connectors with 3" leads. (Similarly, the 10-pin connector CON-2410 plugs onto other meters with eight pins spaced 0.1".)

Can anyone who has used one of these tell me what type of connector will work with them?

I got both this and the PM-123 LCD meter ($11.95) -- to see how each worked. --- I like this one better because its input is "adequately" isolated from the power supply such that it can be used to measure input voltages not sharing a common ground. For example you could use it with your DC power supply to measure current delivered from the positive rail, and at the same time power it from that supply. --- I haven't tested it fully but there seems to be about 10-15K resistance between inputs and power connections -- measured with a DVM and no power to the unit. I'm not sure all would be OK if the inputs were outside the power rails. Even though the price is low, I don't want to do a destructive test to see how much voltage it can take before smoking. :) I am going to get a few more for future power supply uses. --- This unit is slightly smaller in outer dimensions than the PM-128, but it appears that its LCD digits are a bit larger. The only reason I can see for getting the more expensive device is that it has a bezel that makes mounting it easier. However, if you make a cutout to exactly fit this device it snaps in place, looking all to the world just a pretty as if there was a bezel. --- The documentation for this is easier to decrypt than for the PM-128, which I am not sure I have decyphered.