Transcript Applied Math I - University of Oxford

The use of Metric Calipers
Acknowledgment: Thanks to Southwest Wisconsin
Technical College, who provided material from which
this PowerPoint presentation is derived.
Overview
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In this presentation you will learn
about:
The different kinds of calipers.
The components of a typical caliper.
Taking measurements from calipers.
Introduction
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Calipers are used to make precise
length measurements.
Several different kinds of
measurements can be made with a
caliper...
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While both micrometers and calipers
can make outside length
measurements...
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Calipers can also make inside
measurements...
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…and depth measurements.
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There are three types of calipers.
The vernier caliper:
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The dial caliper:
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…and the digital electronic caliper.
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The vernier caliper takes the most skill
to read, and this is the type you will be
using in experiment X.3.
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These are the main features of a typical
vernier caliper:
Small
jaws (for inside
Depth
gauge
Metric
vernierMetric
scale fixed scale
measurements)
Beam
Jaws (for
English
outside
vernier
scalescale
English
fixed
measurements)
Introduction
and
Example 1
Reading a Caliper
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As you are about to see, using a vernier
caliper is not difficult.
You only need to make two readings:
one from the fixed scale and one from
the vernier portion.
Reading a caliper
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Start by obtaining a measurement from
the fixed scale...
This is the fixed scale used
for the metric readings.
Reading a caliper
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Use the zero line on the vernier to
locate your position on the fixed scale.
Reading a caliper
However, since your final reading is
Each number printed on the
normally in millimeters, you need view
metric scale represents centimeters.
these amounts as millimeters.
6 cm
7 cm 8 cm
9 cm
10etc.
cm
Reading a caliper
Just mentally add a 0 (zero) by each
centimeter number.
60 mm70 mm 80 mm90 mm 100 mm
0
0
0
0
0
Reading a caliper: metric
Since there are ten spaces between each
numbered interval, these smallest spaces must
be 1 mm each.
For example, For
this example, note the ten
…this
is 92on
mm...
The smallest
interval
thisinterval.
mmin this
would
be 91…93
mm...
spaces
scale is 1mm.
etc.
Reading a caliper: metric
As you can see in this problem, we have a fixed
scale measurement of 63 mm.
The reading is 63 mm since the
zero line has gone just beyond the
63 mm mark, but hasn’t reached
the 64 mm mark.
Reading a caliper
To finish we must obtain a reading from the
metric vernier scale.
On this scale, each line represents 0.05 mm.
.05 mm
.10 mm
.15
.25
.20
mm
mm
mm
etc.
.30
.35mm
mm
Reading a caliper
We need now to look for the point at which the
This isthe
read
as .50 mm
fixed scale “lines up” with
vernier.
It appears that these two
lines, “line up” the best.
Reading a caliper
So based upon the two readings (one from the
fixed scale, and one from the ruler) the length
must be 63 mm + .50 mm = 63.50 mm
63 mm
+ .50 mm
63.50 mm
Example 2
Reading a caliper
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Let’s try another one
Reading a caliper
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The from
zero line the
is close,
but not scale.
quite
First take a reading
fixed
up to, the 20 mm line. It has gone
Use the zero line beyond
from
the
vernier
the
19that
mm
line
however.
Remember
we
need
to to
read the
fixed scale in terms of millimeters.
19 mm
help.
0
0
0
Reading a caliper: metric
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This is read as .35 mm
To finish, readItthe
vernier
scale.
appears that these two
lines, “line up” the best.
19 mm
.35 mm
Reading a caliper: metric
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The final reading then is 19.35 mm.
19 mm
+ .35 mm
19.35 mm
Example 3
Reading a caliper: metric
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Let’s go through one more example.
Reading a caliper: metric
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Use the zero line from the vernier scale
The zero line is directly above the
to help get a reading
on
the that
fixed
scale.
we need
to read the
8 mmRemember
line.
fixed scale in terms of
millimeters.
8 mm
Reading a caliper: metric
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That’s it! Since the zero line on the
The final reading is 8.00 mm
vernier matched up with a line on the
fixed scale, you quit right there.
Practice
Problem
Reading a caliper
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Do this one on your own. Click to see
the answer.
Reading a caliper
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Thescale
zero line reading.
is close to, but does
Start with the fixed
not quite reach the 67 mm line. It
hasRemember
gone beyond
mmtoline
thatthe
we66
need
read the
however.
fixed scale in terms of millimeters.
66 mm
0
0
0
Reading a caliper: metric
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To finish, read
This is read as .60 mm
the
vernier
scale.
It appears
that these
two
lines, “line up” the best.
66 mm
.60 mm
Reading a caliper: metric
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The final reading then is 66.60 mm.
66 mm
+ .60 mm
66.60 mm