now we'll work with a verer caliper the
way this works is that there is again an
upper and lower scale here this is the
CM 0 1 2 3 on this axis here and then on
the upper we have inches which we're
going to neglect for our uh use and then
this is the lower scale down here 0 1 2
3 up to 9 and then zero again is the
minor
scale when it's shut the Veria caliper
isn't measuring anything that is then
the zeros on the major and minor axes
line up so we can see that this zero on
the minor scale and this on the major
scale they line up quite well and you'll
notice nowhere else does that occur that
is the the markings on the minor and
major scale lineup except again at zero
here and
there we'll put our measurement object
here between the teeth of the verc scale
and and we'll close it uh when we're
measuring something there's a flat side
here and we'll want to put our device in
that and then close it uh with a little
bit of pressure and then with that uh
value we're going to see what the
measurement is on the major
scale it's the question of where does
the zero on the minor scale line up with
the major scale so here we have a zero
on the minor scale which is a little
past
this hash mark here so that's 5 6 7 it's
a little more than 7 cm the question is
how much more than 7 cm is
it since the zero here doesn't line up
with the major scale exactly we need to
find where on the minor scale it does so
there's uh no match
here until we reach say the six value so
on the minor scale the six Mark lines up
pretty well you could even say the seven
Mark lines up better so we'll take this
seven as our minor scale
measurement now the question is how do
we combine this 0.7 CM measurement on
the major scale with the seven mark on
the minor scale the answer to that is
over on the far side of our caliper
there's a little marking that says
0.05
mm this tells us the smallest unit of
measurement for the
caliper so now when we look back this
zero on the minor scale is somewhere
between 7 and8 on the major scale so
this gives us some confidence that our
measure is
correct now that we know the smallest
unit of measure on the minor scale is
0.0 05 mm that tells us what this 7
means each of these small marks from
here to here is 0.05 mm and so since
this this is seven and then there are
two marks per increment there are
actually 14 of these small
measurements the way we'll combine these
sets of measurements the
0 05 mm on the minor scale as the
smallest measurement with the major
scale of 7 cm
is we'll take the major plus the number
of minor increments in this case 14 and
then multiply that number times the
smallest measure so what we get back
after we convert to the correct units of
centimeters in this case is 77 CM with
an accuracy of plus or minus
.5
CM as a check this makes sense because
the value should be between
7 cm and8 cm and if we look back at our
original
measurement we see that our zero mark on
the minor scale is close to the8 so 77
CM makes
sense now as an example of what happens
if our scale is slightly different if if
we're using uh a different measure and
we come up upon the case where the zero
on the minor scale lines up with an
increment on the major scale scale for
instance now I see that the zero on the
minor scale lines up very well with 1.7
on the major
scale what that does for our calculation
is we still have a major scale of 1.7 CM
but now our minor measurement is zero
increments and we multiply that times
our smallest measure of 0.05 mm and what
we get back is a more precise measure of
1.70 plus or minus 0.5
cm