On Fri, 2 Mar 2018 18:18:39 -0700, Bob La Londe
wrote:

Every dial caliper I own (I think every one) or have owned says
shockproof right on the dial. Exactly what shock are they proof
against? Certainly not being dropped.

Dial pointer jumping, maybe? Crystal integrity?

--
Shake off all the fears of servile prejudices, under which weak minds
are servilely crouched. Fix reason firmly in her seat, and call on her
tribunal for every fact, every opinion. Question with boldness even the
existence of a God; because, if there be one, he must more approve of
the homage of reason than that of blindfolded fear.
-- Thomas Jefferson