vernier calipers

Vernier, Dial, and Electronic Digital Calipers

Session 3

Shop Tools and Techniques 2

Used to lock readings into place

Parts of the Vernier Caliper

Manufactured with both 25- and50-division vernier scales

Bar of 25-divisionvernier scale graduatedsame as micrometer

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Measuring a Workpiece• Remove all burrs from workpiece• Clean surface to be measured• Open jaws enough to pass over work• Close jaws against work and lock

right-hand clamp screw• Turn adjusting screw until jaws just

touch work surface• Lock clamp screw on movable jaw• Read measurement

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Inch Vernier Caliper

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Inch Vernier Caliper

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Inch Vernier Caliper

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Reading the Measurement

A vernier caliper reading of 1.464 in.

1 x 1.000 = 1.000

4 x 0.100 = .400

1 x 0.050 = .050

14 x 0.001 = .014

1.464 in.

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Metric Vernier Caliper• Parts same as inch vernier• Main scale graduated in millimeters

• Every main division numbered, each 10 mm• Fifty graduations on sliding scale with every

fifth one numbered• 50 graduations occupy same space as 49

graduations on main scale (49 mm)• 1 vernier division = 0.98 mm so difference between

1 main scale division and 1 vernier division = .02 mm

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Metric Vernier Caliper

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Metric Vernier Caliper

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Reading a Metric Vernier• Last numbered division on bar to left of

vernier scale represents number of millimeters multiplied by 10

• Note how many full graduations showing between this numbered division and zero• Multiply number by 1 mm

• Find line on vernier scale that coincides with line on bar and multiply by 0.02 mm

• Add for total reading

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Dial Caliper• Dial indicator, hand attached to pinion,

mounted on sliding jaw• Accurate to within 0.001 inch.• 1 revolution = .100 or .200 in. of travel

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Dial Caliper

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Dial Caliper

Making OD

Measurement

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Dial Caliper

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Dial Caliper

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Dial Caliper

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Dial Caliper

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Dial Caliper

Left Hand Version

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Reading Dial Caliper• Read number to left of moveable jaw.

•Reading is 0.500 inch

• Read dial face•Reading is .028

0.500 + 0.028

0.528

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Reading Dial Caliper

1.300

+ 0.048

1.348

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Reading Dial Caliper

2.100

+ 0.033

2.133

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Reading Dial Caliper

54.00

+ 0.34

54.34

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Reading Dial Caliper

30.00

+0.04

30.04

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Digital Electronic Caliper• Can provide readings to resolution of

.0005 in. or 0.01 mm at touch of button• No rack, pinion or glass scale• Can connect to Statistical Process Control

(SPC) equipment for inspection purposes

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Digital Electronic Caliper

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Digital Electronic Caliper

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Digital Electronic Caliper

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Dial or Digital Caliper Base Attachments

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Vernier Depth Gage• Measures depths of holes, slots and recesses• Read same as

standard vernier caliper

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Vernier Height Gage

• Variety of sizes:• 12-72 in. or 300-1000 mm.

• Accuracy .001 in 0.02 mm)

• Offset scriber• Attachment that permits

setting heights from face of plate

• Depth gage attachment

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Vernier Height Gage

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Dial Height Gage

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Digital Height Gage

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Precision Height Gage• Provides quick and accurate method of setting

any height within range of instrument• Eliminates need for calculating and assembling

gage blocks• Surface plate used as reference surface

• Made from hardened, ground round steel bar• Measuring steps spaced at 1.000-in (25-mm)• Bar raised or lowered by micrometer thimble

graduated by steps .0001 in or 0.002 mm• Can be used for precision inspection and also

connected to statistical process control equipment

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Precision Height Gage