"Nick Mueller" wrote in message
...
Harold and Susan Vordos wrote:

So you're suggesting that a long travel indicator isn't capable of
measurements?

G Every measurement is done by comparison!
But I don't know what a long travel indicator can measure better than one
with a short travel. Except ... longer travel.


You've missed the point. Long travel indicators are properly calibrated
for measurement--and are generally used in that capacity. Your statement
"Any dial indicator can only compare" isn't true.
I concede, you can always conclude that they are comparing against the
calibration standard------but that's not the point---which is, a long travel
indicator is able to measure. A DTI is distinctly different from a long
travel indicator in that it is specifically made for comparison readings,
due in part to the adjustable tip, which includes parallax error, a function
of the angle of the tip. None of that is an issue with a long travel
indicator, assuming it is set up in the proper attitude in relationship to
the work in question.

Harold