Date post: | 21-Aug-2015 |
Category: |
Education |
Upload: | rai-university |
View: | 250 times |
Download: | 2 times |
Measuring Instruments
Course: DiplomaSubject: Applied Science Physics
Unit: IChapter: III
Use of Vernier Caliper
Vernier Caliper can be used to measure diameter, thickness very accurately.
The Mission Covenant Church Holm Glad College1
2
0 cm 2 cm1 cm
0 10
Main Scale
Vernier Scale
Main Scale
3
Vernier Scale4
How to read the result
of measuring by using
the Vernier caliper
What is the result of measuring ?5
What does it mean ?
6
6 mm
7
What does it mean ?8
( 2 x 0.1 ) mm9
6 mm
( 2 x 0.1 ) mm
The result of measuring is ( 6 mm + 0.2 mm ) = 6.2 mm
10
What is the result of measuring ?
11
The result of measuring is :
( 3 mm + ( 7 x 0.1 ) mm ) = 3.7 mm
0 cm 2 cm1 cm
0 10
Main Scale
Vernier Scale
X 0.1 mm
Least Count = Value of the smallest division on MS/ Total number of division on VS
L.C = 1mm / 10 = 0.1 cm / 10 = 0.01cm
0 cm 2 cm1 cm
0 4 8 6 2 10
Main Scale
Vernier Scale
X 0.05 mm
Measuring Internal Diameter
Use the inside jaws of the caliper as shown
The Mission Covenant Church Holm Glad College
12
Measuring External Diameter
Use the outside jaws of the caliper as shown
The Mission Covenant Church Holm Glad College
13
Measuring Height of Bar.
14
Measuring Depth of a Hole
Use the depth gauge of the caliper as shown
The Mission Covenant Church Holm Glad College
15
Measuring Instruments
• Vernier Caliper• (a) Positive zero error• Zero error = +0.04 cm.
16
Measuring Instruments
• Vernier Caliper
(b) Negative zero error• Zero error = -0.02 cm.
17
Structure of the Micrometer
18
Scale description : Main scale & Circular scale
19
Least Count• Least Count = Pitch of the Micrometer / Total
number of circular scale division• Least Count = 1 / 100 = 0.01mm
= 0.001cm
20
21
Measuring Instruments
22
Dial Caliper The dial Caliper has seven main components: a slide scale, lock screw, thumb adjustment wheel, measuring jaws (inside & out), dial with measurements of 0.001 inch, depth rod and a bezel.23
Dial CaliperTry this one
24 25
Dial Caliper
• Answer is • 1.931
Read the Measurement 1
26
Read the Measurement 2
27
Read the Measurement 3
28
Read the Measurement 4
29
Read the Measurement 5
30
Description of the Spherometer
• Instrument that measures the surface power (D) associated with the lens surfaces.
31
Functional Principle
Supporting the legs on the lens surface, the movement of the center leg, is translated to the scale, giving the value of the surface power of the surface.
Positive value in convex surfaces.
Negative value in concave surfaces.
32
Zero errorAdjustment or Calibrating the instrument to zero:
When placing the instrument on a flat polished surface, the scale must mark 0.00 D.
If not, all previous measurements will be affected by this value.
The measurement will be a result of the following equation:
Psur: Value given by spherometer when place on flat surface.
Psph: Value given by spherometer when placed on one of the curved surfaces of the lens.
surPspherePP
A thermometer is an instrument that is used to
measure temperature.
The temperature tells us how hot or cold something is.
33
Temperature is measured using two scales: Celsius and Fahrenheit.
212100 C F
Galvanometer
• The galvanometer is the "classic" device to measure current
• Based on the fact that a wire carrying current in a magnetic field feels a force
43
• The current flows through a coil in a magnetic field
• The coil experiences a torque proportional to current
• The movement of the coil is "opposed" by a spring
• The deflection of the needle is proportional to current
44
34
35
36
• Rsh = "shunt" resistance
• The current I divides itself between the coil and the shunt– I = IC + Ish
• By Ohms's law, Vab = IC RC = Ish Rsh
• Ish = IC (RC/Rsh)• I = IC + Ish = IC (1 + RC/Rsh) If RC and Rsh are known, measuring IC is
equivalent to measuring I• Furthermore, I is still proportional to IC, which is
proportional to the deflection of the needle• Thus, by "switching in" different shunt resistances I
can effectively change the "range" of my current measurement
37
Electrical Measuring Instruments Ammeter
38
Electrical Measuring Instruments
Voltmeter
39
40 41
42
43
44
45
46 47
48
4349
5352
5051
REFERENCE BOOKS AUTHOR/PUBLICATION
ENGINEERING PHYSICS S S PATEL (ATUL PRAKASHAN)
MODERN ENGINEERING PHYSICS
A S VASUDEVA
ENGINEERING PHYSICS K. RAJGOPALAN
Image reference links1. http://www.slideshare.net/stootypal/vernier-caliper2. http://www.tutorvista.com/content/physics/physics-i/measurement-and-experimentation/vernier-calliper
s.php
3. To 11) http://i.imgur.com/2QqIQsU.png12. http://postimg.org/image/56z59zrtp13. http://postimg.org/image/hkbzgwhi514. http://www.muelaner.com/wp-content/uploads/2013/07/Calipers-Bolt2.png15. http://postimg.org/image/8f3mn1e3h16. http://i.imgur.com/V5pHuiR.png17. http://i.imgur.com/7TShrLa.png18. http://www.technologystudent.com/equip1/microm1.htm 19. http://www.indiastudychannel.com/attachments/Resources/143680-5126-Micrometergauge.jpg20. http://www.cyberphysics.co.uk/practical/skills/micrometer2.gif21. http://i.imgur.com/cxlIcvh.png22. http://www.tutorvista.com/content/physics/physics-i/measurement-and-experimentation/screw-gauge.ph
p
23. http://0801.nccdn.net/1_5/2ff/292/391/dial-calipers.png24. http://www.pixentral.com/pics/1CpY49KAqUFdhu88HhJTCL87z92J.png25. http://i.share.pho.to/1b2ffae6_o.png26. http://i.share.pho.to/dc6d8ee9_l.png27. http://i.share.pho.to/7891c224_l.png28. http://i.share.pho.to/38135259_o.png29. http://i.share.pho.to/cb289234_o.png30. http://i.share.pho.to/79e115ad_l.png31. http://www.phys4arab.net/vb/showthread.php?t=30682
Image reference links32. http://i.share.pho.to/9e2475b4_o.png33. http://i.cubeupload.com/ERLcXH.png34. To 36) http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/galvan.html37. http://i.cubeupload.com/ERLcXH.png38. http://i.cubeupload.com/7Kmkuj.png39. http://i.cubeupload.com/pMmBAH.png40. http://i.cubeupload.com/Z74xh1.png41. http://cubeupload.com/im/M19NIc.png42. http://cubeupload.com/im/CFIlLm.png43. http://cubeupload.com/im/dk5I7m.png44. http://i.cubeupload.com/xs7kyV.png45. http://carcraftstore.com/images/products/thumb/AM3586.jpg46. http://i.cubeupload.com/2zVJ6H.png47. http://i.cubeupload.com/5pAyyo.png48. http://cubeupload.com/im/UlwSGc.png49. http://i1.olxthailand.com/df/0/ui/post/2014/10/02/8/t/f4c0fe31a19370caec10864f7b35c194.jpeg50. http://static.coleparmer.com/large_images/90000_53.jpg51. http://www.entest.net/product_images/j/372/312FC__10343_thumb.jpg52. http://dicoworldwide.com/picoasi-2.htm53. http://imgur.com/lj2uzNU
END