http://bzuiam.webs.com/

2. THE CALIPERS
“Calipers are traditionally means of
assessing dimensions”
•COMMONLY USED WITH STEEL RULES OR
OTHER MEASUREMENT INCREMENTS
•Generally provide a dimensional accuracy
of 1/64inch

3. FOR MORE HELP CONTACT ME
Muhammad Umair Bukhari
Engr.umair.bukhari@gmail.com
www.bzuiam.webs.com
03136050151

4. TYPES OF CALIPERS
 Direct reading calipers
Dial caliper:
 Simplest form of mechanical caliper
 Displays a reading directly
Electronic digital caliper:
 Gives more accurate reading than simple calipers
 Automatically switchable from english to the
matric system

5. Dial caliper
Electronic Digital caliper

6. VERNIER CALIPER
 A measuring instrument consisting of an L-
shaped frame with a linear scale along its longer
arm and an L-shaped sliding attachment with a
vernier
 used to read directly the dimension of an object
represented by the separation between the inner
or outer edges of the two shorter arms.
 Accuracy up to 1/1000 inch or 0.05mm
 They are manufactured for either internal or
external measurements

7. PARTS OF A VERNIER CALIPER:
 Outside jaws: used to measure external
diameter or width of an object
 Inside jaws: used to measure internal diameter
of an object
 Main scale: scale marked every mm
 Main scale: scale marked in inches and fractions
 Vernier gives interpolated measurements to
1/10 mm or better
 Vernier gives interpolated measurements in
fractions of an inch

8. PARTS OF VERNIER CALIPER:
Main scale:
Each inch on the main scale is subdivided into 10
equal parts & each of these part is again
subdivided into quarters…..
Thus each individual graduation on the main scale
represents 1/40th of an inch………
Vernier scale:
 The vernier scale contains 25 subdivisions in the
same total length embraced by the 24
subdivisions on main scale…..thus each
individual graduation on the vernier scae
represents 1/1000th of an inch…………

9. READING THE VERNIER CALIPER

10. VERNIER DEPTH GAGES:
 These are used to measure the depths of holes,
recesses, slots, counterbores, and so forth
 It is essentially a depth rule with vernier
attachments and markings
 The care should be taken during usage

11. MICROMETER SCREW GAUGE
 A device incorporating a calibrated screw used
widely for precise measurement of small
distances
 Can be used for inside & outside measurements
 It is more versatile and accurate of the hand-held
measuring device
 Can give dimensions accurate upto 0.001 inch

12. MICROMETER(CONTD………)
 The principal of the micrometer is:
“A Screw turning in a Nut and end of the screw
advancing towards or receding from the opposite
“Anvil “of “C” frame”
Adjusting nut
Anvil
Screw threads
C frame

13. PARTS OF MICROMETER:

14. MICROMETER(CONTD….)
 The length of the sleeve scale is divided into
10 equal parts of an inch….and each tenth part is
again subdivided into 4 equal parts
 The micrometer thimble has 25 graduations
and each graduation is equal to the 1/1000th of an
inch
 Rotating the thimble for one line moves the
spindle longitudinally 1/25 of .025" or .001" of an
inch;Twenty five divisions indicate a complete
revolution, .025 or 1/40 of an inch.

15. READING THE MICROMETER
•The "1" line on the sleeve is
visible, representing .100“
•There are 3 additional lines
visible, each representing .025"
.025".
•The calculation would be 3 x
.025" = .075"
Line "3" on the thimble coincides
with the reading line on thesleeve,
each line representing .001"
The calculation would be 3 x .001"
= .003“ The micrometer reading is
"