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


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


Inch Vernier Caliper


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.


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


Metric Vernier Caliper


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


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


Dial Caliper


Dial Caliper

Making OD

Measurement


Dial Caliper


Dial Caliper

Left Hand Version


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


Reading Dial Caliper

1.300

+ 0.048

1.348



2.100

+ 0.033

2.133



54.00

+ 0.34

54.34



30.00

+0.04

30.04


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


Digital Electronic Caliper


Dial or Digital Caliper Base Attachments


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

standard vernier caliper


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


Vernier Height Gage


Dial Height Gage


Digital Height Gage


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


Precision Height Gage

vernier calipers

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