Transcript Precision Measurement

Forging new generations of engineers
PRECISION MEASUREMENT
HELP !
Precision Instruments Explained
•
•
•
•
•
MICROMETERS
CALIPERS
DIAL INDICATORS
GAGE BLOCKS
FEELER GAGE
How Precise Do I Need To Be ?
We need to be able to accurately
measure parts to 1/1000 of an inch
or as a decimal - .001
Tenths
.001
Hundreds
Thousands
Decimal to Fraction
Conversions
.125 – 1/ 8”
.250 – 1/ 4”
.375 – 3/ 8”
.500 – 1/ 2”
.625 – 5/ 8”
.750 – 3/ 4”
.875 – 7/ 8”
1.00 – 1”
.0625 – 1/ 16”
.1875 – 3/ 16”
.3125 – 5/ 16”
.4375 – 7/ 16”
.5625 – 9/ 16”
.6875 – 11/ 16”
.8125 – 13/ 16”
.9375 – 15/ 16”
Micrometers
Micrometer Set 1” To 6”
Micrometer Parts
Ratchet Screw
Thimble
Thimble Scale
Barrel
Barrel Scale
Frame
Spindle
Anvil
Micrometer Standards
Zeroing A Micrometer
To zero micrometer scale use spanner wrench,
place it in small hole as shown and turn
Divisions
Barrel
Scale
0.001”
Division
Thimble
Scale
0
1
2
3
0
0.025” Division
0.100” Division
Reading a Micrometer
• Observe the greatest 0.100-inch
division on the barrel scale.
• Observe the number of 0.025-inch
divisions on the barrel scale.
• Add the thimble scale reading (0.001inch division) that coincides with the
horizontal line on the barrel scale.
Reading a Micrometer
• Observe the greatest 0.100-inch division
on the barrel scale. (three 0.100” = 0.300”)
0
1
2
3
10
5
Reading a Micrometer
• Observe the number of 0.025-inch
divisions between the 0.300-inch mark
and the thimble. (two x 0.025” = 0.050”)
0
1
2
3
10
5
Reading a Micrometer
• Add the thimble scale reading that coincides
with the horizontal line on the barrel scale.
(eight 0.001” = 0.008”)
Micrometer
reading
0.300”
0
1
2
3
10
0.050”
+ 0.008”
0.358”
5
Types Of Calipers
Venier
Dial
Digital
Parts Of A Caliper
Inside Measuring Jaws
Depth Gage
Dial .001
Outside Measuring Jaws
Bar Scale
Reading Calipers
Divisions
1.000” 0.100”
0
1
0.010”
0.001”
Reading Calipers
• Observe the greatest 1.000” division
1.000”
0
1
Reading Calipers
•Observe the greatest 0.100” (0.100” = 0.600”)
0.600”
0
1
1.000”
0.600”
Reading Calipers
•Observe the greatest 0.010” (0.010” = 0.000”)
0.000”
0
1
1.000”
0.600”
0.000”
Reading Calipers
•Observe the greatest 0.001” (0.001” = 0.005”)
0.005”
0
1
1.000”
0.600”
0.000”
+ 0.005”
1.605”
Dial Indicators
1/2”, 1”, AND 2” TRAVEL
Dial Indicator Parts
Bezel
Pointer
Dial
Graduations
Shank
Stem
Contact
Dial Indicator Scale
EACH DIVISION = 1\1000 =.001 INCH
Dial Indicator
Mounted On Magnetic Base
Dial Indicator
• Mounted on a support
• Size range from 1 inch
to 4 1/2 inches in
diameter
• Balanced scale (read
plus or minus)
• Continuous scale
(dimensions)
• Scales range from .002”
This setup is used to check for
to 1.000”
end play on a crankshaft.
Gage Blocks
Gage blocks are very accurate measuring
standards to 1\1,000,000 in.
Gage Blocks
Five Individual Gage Blocks From Set
Ringing Blocks Together
Ringing Two Blocks Together So They Attach
Gage Blocks
Gage Blocks Rung Together To Give An Accurate Size
Feeler Gage
• Thin strips of
steel or brass
• Available in
various thickness
• Measured in
thousandths of an
inch
• Millimeter
Feeler Gage
Here a feeler gauge is checking the valve adjustment
Measuring Tools Summary
• MICROMETERS
• CALIPERS
• DIAL INDICATORS
• GAGE BLOCKS
• FEELER GAGES
Measuring Questions
•
•
•
•
•
•
•
•
NAME 5 TYPES OF MEASURING TOOLS.
NAME THE TWO SYSTEMS USED TO MEASURE.
WHAT 3 MEASURING JOBS CAN A CALIPER DO?
HOW IS A FRACTION CHANGED TO A DECIMAL?
WHAT ARE GAGE BLOCKS AND HOW ARE THEY USED?
WHAT IS A DIAL INDICATOR AND ITS USES?
NAME THE PARTS OF A MICROMETER.
LIST 5 PRECAUTIONS TO PRACTICE WHEN USING
PRECISION MEASURING TOOLS.