This can have significant effect on measurementsmall changes in
height measurement error, greatly changes the angle result
Some authorities do not recommend using sine instruments on
angles over 45 degrees
Sine blocks are wide sine bars
Sine plates are w
Geometry:
The most common of the trigonometric functions
for right angle triangles

Sine of an angle= Opposite/Hypotenuse

Cosine of an angle= Adjacent/Hypotenuse

Tangent of an angle= Opposite/ Adjacent
 SOH CAH TOA is a memory aid for the above equa
Calipers:
Calipers are transfer instruments
Measurement with all these instruments introduces error
nstruments that require contact depend upon the feel of the user for
precision
 Cleanliness will promote reliability, but only skill will provide
accuracy
Discrimination is the finest of the scale divisions of an instrument.
Itisthesmallestdivisionofthescalethat can be read reliably.
Advantages
Amplification is achieved by designnot on moving parts which could
wear and go out of calibration
No interpolatio
Imperial Procedure:
1) Select nearest whole inch to the left of the vernier scale.
Add next whole 0.100 inch
Add next whole .025 inch Add nearest .001 from vernier scale
Metric Select nearest whole mm
Add vernier scale as 0.xx eg: 10.04mm, 22.65 mm
A scal
Interpolation:
The only acceptable time to interpolate is when you cannot find an
instrument discriminating enough to provide an accurate
measurement
Sources of Error
Inherent instrument or tool error
Can eliminate this by choosing a quality steel rule
A
Types of Mircometers:
Outside micrometer Inside micrometers Depth Gauges
Metric micrometers allow one to measure to .002 mm
Imperial micrometers allow one to measure to .0001 in.
Note the rule of ten if one wanted to measure reliably to .002 mm one
would
In the example of the hair we have indicated only one significant
figure
This means we think 3 is a reasonable value, but we are not sure of
the next digit (second significant figure)
The greater the accuracy of our measurementthe larger the number
of si
The designated micrometer size is its largest opening, not the range
Typical mic is 01 or 025mm Micrometers are available over 400
mm in size ( 16)
Available in both imperial and SI units
Regardless of size, the range is usually limited
to 25 mm ( 1 inc