so we are going to review how to read
verer calipers these are metrics so all
of this will be in millimeters and
centimeters these are more precise than
rulers because you are actually
measuring in t of a millimeter instead
of just millimeters so these are
preferred for when we do calculations of
angle of
impact uh when you look at the part of a
caliper you have the base ruler here and
then you have the
slider and the slider portion is where
you're going to spend most of your time
focusing on what is going to be your
measurements we are going to be focusing
on the outside measurements so you're
going to be looking at the top bar of
this particular
slider so if I were to take an
object I'm going to gently pinch
until I've encased the entire object and
then you can remove the object or you
can keep it in there that is your
preference and then at this point you
don't have to do anything else with the
calipers in order to get an accurate
measurement the first thing you're going
to look at is your base
number your base number is where this
zero on the outside bar of the slider is
lined up on the main base
ruler so if I look this zero is lined up
in between 21 and 22
mm that means that the measurement is
going to be
21 something so the next part of how to
read calipers is looking for where your
decimal is and this is where you're
going to pay special close attention to
these hash marks up at the top so on the
outside slider bar you'll notice 0.1 2.
3.4.5 Etc you're going to look at these
hash marks and you're going to find the
one that is lined up with a line on the
base ruler below
it in this
case I'm looking and I
see 05 seems to be the hash mark that is
lined up directly with one of the lines
below
it that indicates to me that this
reading would be
21.5
mm when you go to do the decimal it is
not important what the number is on the
base
ruler that is only important when you
find the base number when you line up
with your zero the decimal is just
indicated by which line is perfectly
lined
up
if I were to change
it as such and the zero is lined up with
the 21 for my base
number this particular example indicates
that this is
21.0 you know you have a whole number
when the 0er and the 1.0 are both
perfectly lined
up so now what we're going to do is
we're going to use calipers to measure
length and width of a blood drop when
you measure a blood drop you're only
concerned with the
major part of this batter you will not
be taking into account the tail so the
first thing I will do is I will measure
the length I'll take my
calipers I'm going to line them
up
now that was a little difficult because
the calipers tend to wobble so a trick I
like to do is if I flip the calipers
over it's nice and flat and all I have
to
do is move the sliders so again I line
it
up and that gives me the measurement I
need now all I have to
do is read my pair of calipers
so the
length is going to be represented by
this particular number so again we look
at the base number and I see that it's
11 12 13 it's in between 13 and 14 so I
know it's going to be 13 point something
so then I look at my hash marks and I
figure out which one is exactly lined
up and to me it looks like 04 is the
winner so it's 13.4 4 mm so our
length will be written down as
13.4 I can take the same
drop line up one side move the slider to
the
other the width is obviously going to be
much more narrow than the length so I
look at my base number and it looks in
between 2 and
three find my hash
mark looks like it's
2.9 I would write those down and then I
would calculate my r
value