I found that my Instromet sunshine recorder was registering 1/100th of an
hour every 37.5 seconds leading to it under-recording (after using it for 12
months)

I discovered there is an adjustment on the circuit board and using a
stopwatch it was quite easy to get the timing to 36 seconds per 1/100th on
the display.

Recently I timed it for 6 hours sunshine and found that it now under-records
by 33 seconds for 6 hours duration, which is about as good as I reckon it
could be.

How long it will be before it needs adjusting again is anybody's guess.
________________
Nick G
Otter Valley, Devon
80 m amsl
http://www.ottervalley.co.uk