I see that Meggers start to accumulate, just like Avometers...
A second Circuit Testing Ohmmeter has just smuggled its way into the collection. A different model, with two ranges: 0 to 500 ohms, and 100 ohms to 50,000 ohms. This one came with an original set of test leads and a nice 1943 Megger "hand-book on continuity and polarity testing". It even had a good battery inside it.
A small amount of corrosion was removed from the battery terminals with a rotary wire brush and a spray of Servisol. The meter worked, but the high range switch was intermittent and the readings were inaccurate, so the lid came off for a look inside.
Servisol dealt with the intermittent range switch contacts. The meter indicated below zero on the low range with the probes shorted, and above infinity on the high range with the probes apart, so I was looking for a mechanical zero adjustment. There wasn't one, nor any electrical adjustment. On closer inspection, the pointer looked slightly bent to the left near where it's attached to the moving coil assembly, so with great care and some trial and error I made some gentle minor adjustments. This has resulted in the meter now properly indicating zero, infinity and all points in between.
The test current on the low ohms range is around 30-35mA and the probe without the pushbutton is positive.
Phil