If the bare meter movement is showing a loss of sensitivity, my
first guess would be a weakening field magnet. It would be a
bit unusual for a modern instrument, however....

Pete


Thank you for your suggestion.

After completely disassembling the multimeter, I got access to the front spring
of the movement and noted that first turn had just overlapped the spring binding
post, possibly due to a shock. Just touching the spring, it went back to normal
with no deformation at all. Now the full scale current is exactly what it should
be.

What amazes me is that I could not find any visible adjustment point (e.g. a
variable magnetic shunt). Evidently they were able to produce very precise
meters requiring no adjustment.

73

Tony I0JX