Michael Koblic wrote:
"Bill McKee" wrote in message
m...

"Michael Koblic" wrote in message
...

I have three sets of cheap digital calipers bought in Canadian Tire. The
have all been working fine and agree with a micrometer to within 0.001".
Two weeks ago I tried to use the one I keep in the workshop to measure
something of the order of 4" when the calipers refused to measure anything
past 1.5". I brought them into the house where they started working fine
as soon as they warmed up.

The second set did exactly the same thing today.

The temperature in the workshop is 9.5 deg C.

Replacing the battery made no difference. What is the likely cause?

--
Michael Koblic
Campbell River, BC
'

I would clean the edge of the calipers and see if the roller is slipping.
Being cold the bearing may have enough drag to slip on the caliper.


All three are doing this. Cleaning the edges did not help. A quick blast
with a hair-dryer did. I suspect the condensation theory is closest to the
mark. It is interesting that the calipers will measure OK up to 2", it is
only when you go past that that the error begins to show. I take it that
this is because the first two inches of the scale are protected by the
housing during storage.

It's not a big deal as long as one is aware of it.


Is the 2" point where you may have been holding it in your hand?. I have
a Mitutoyo scale and if I hold it long enough at one point then travel
the head across there then it will often flag an error, just leaving it
for a minute or 2 will sort the problem. I assume it's moisture from my
hand on the measuring surface cover.