Digital calipers

[Ron Nossaman]

> It is important to develop a “feel” for your micrometers and calipers 
> when closing them against your specimen and closing them.  Without this 
> important control, you will not get consistent, dependable 
> measurements.  BTW, these instruments must be stored in their closed 
> position to keep them clean and corrosion free.
> 
> Paul C

I bought one of the $15 Harbor Freight digitals a year or so 
ago, and have been more impressed with it than I expected to 
be. I've found, with either dial, vernier, or digital 
calipers, that the thumb wheel is definitely not your friend 
if you need accuracy. Accuracy increases considerably and 
repeatably by squeezing the jaws onto the measuree by finger 
pressure directly on the jaws, on either side of said 
measuree. This takes the flex out of the system, gets you into 
the designed intent of usage of the system, and closer to a 
real and actual dimensional figure than the usual vague 
committee approximation we typically expect from calipers. Not 
that it ain't possible (nay, likely) to screw up a given 
measurement taken with any tool we care to name, but there are 
approaches and methods that limit and minimize erroneous 
measurement. Erroneous deductions extrapolated from inaccurate 
measurements are, unfortunately, unavoidable and, largely 
(also unfortunately), inevitable.

We loves our tools, however, despite their limitations in 
overcoming our own limitations.

At least I does...
Ron N