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Angular_Measurement.ppt
This document discusses angular measurement tools and techniques. It covers: - Angular units such as degrees, minutes, and seconds and how they relate to each other in dividing a circle. - Common tools for measuring angles including protractors, combination sets, universal bevel protractors, sine bars, and sine plates. - How to use a vernier protractor and inclinometer to measure angles and how to convert between decimal degrees and degrees-minutes-seconds.
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Angular_Measurement.ppt
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- 2. 2 Angular Measurement • Circlesare divided into 360 equal parts, each being a degree. • Each of these degrees can be evenly divided into 60 equal parts. These parts are called minutes. • These minutes can be evenly divided into 60 equal parts. These parts are called minutes.
- 3. 3 Angular Measurement • 1Circle = 360 Degrees ( 360° ) • 1 Degree ( 1° ) = 1/360th of a Circle • 1 Degree ( 1°) = 60 Minutes ( 60' ) • 1 Minute ( 1' ) = 1/60th of a Degree • 1 Minute ( 1') = 60 Seconds ( 60" ) • 1 Second ( 1" ) = 1/60th of a Minute
- 4. 4 Angular Measurement • Theunit of degree can also be divided into either decimal or fractional parts and is referred to as decimal degrees or fractional degrees respectively. • 1½ Degree = 1.5 Degree ( 1.5°) • 87¼ Degrees = 87.25 Degrees ( 87.25° )
- 5. 5 Angular Measurement • Minutesand seconds can each be expressed as decimal or fractional degrees. • 1 Minute ( 1' ) = 1/60th of a Degree = 0.01667° • 1 Second ( 1" ) = 1/60th of a Minute = 0.01667'
- 6. 6 Angular Measurement Change 5°25'to decimal degrees Divide the minutes by 60 Add 0.4167 to 5 = 5.4167° 5°25' = 5.4167° 25 divided by 60 = 0.4167
- 7. 7 Angular Measurement Change 27°52'35"to decimal degrees Divide the seconds by 60, add to minutes Divide the minutes by 60, add to degrees 27°52'35" = 27.8764° 35 divided by 60 = 0.5833 Added to the 52 minutes, it becomes 52.5833' 52.5833 divided by 60 = .8764 Added to the 27 degrees, it becomes 27.8764°
- 8. 8 Angular Measurement Change 47.75°to degrees, minutes, and seconds Multiply the decimal portion by 60 This decimal .75 becomes 45 minutes. Add this to the degrees. 47.75° = 47°45' 75 x 60 = 45 Since there isn't any decimal portion after the 45, no further work is necessary.
- 9. 9 Angular Measurement Change 82.3752°to Degrees, minutes, and seconds Multiply the decimal portion by 60 Multiply the decimal minutes by 60 82.3752° = 82°22'30.72" 0.3752 x 60 = 22.512 (the 22 becomes the minutes) Now add this to the degrees 0.512 x 60 = 30.72 Now add this to the degrees and minutes to become seconds. 82.3752° = 82°22.512'
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- 11. 11 Angular Measurement • Mostcommon tools • Simple Protractor • Multi-Use Gage • Combination Set • Universal bevel protractor • Sine bar • Sine plate
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- 14. 14 Multi-Use Gage Pre-set positionsfor 45 and 90 degrees, 59 degree drill point angle, and whole degree increments.
- 15. 15 Multi-Use Gage Pre-set positionfor 90 degrees.
- 16. 16 Multi-Use Gage Pre-set positionfor 45 degrees.
- 17. 17 Multi-Use Gage Measuring 59degree drill point angle.
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- 19. 19 Combination Set Protractor Wholedegree increments
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- 24. 24 • Precision angles towithin 5' (0.083º) • Consist of base • Vernier scale • Protractor dial • Sliding blade • Dial clamp nut Universal Bevel Protractor
- 25. 25 Vernier Protractor • Usedto measure obtuse angle (90º-180º) • Acute-angle attachment fastened to protractor to measure angles less than 90º • Main scale divided into two arcs of 180º • Scale divided into 12 spaces on each side of 0 • If zero on vernier scale coincides with line on main: reading in degrees
- 26. 26 Reading a Vernier Protractor •Note number of whole degrees between zero on main scale and zero on vernier scale • Proceeding in same direction, note which vernier line coincides with main scale line 50º Fourth • Multiply number by 5' and add to degrees on protractor dial 4 x 5'= 20' Reading = 50º 20'
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- 28. 28 Sine Bars • Usedwhen accuracy of angle must be checked to less than 5 minutes • Consists of steel bar with two cylinders of equal diameter fastened near ends • Centers of cylinders exactly 90º to edge • Distance between centers usually 5 or 10 inches and 100 or 200 millimeters. • Made of stabilized tool hardened steel
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- 30. 30 Sine Bars • Usedon surface plates and any angle by raising one end of bar with gage blocks • Made 5 inch or in multiples of 5 or 100 millimeters or multiple of 100 • Distance between lapped cylinders. • Face accurate to within .00005 in. in 5 inches or 0.001 mm in 100 mm.
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