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# distance measurements

الكلية كلية الهندسة     القسم  الهندسة المدنية     المرحلة 2
أستاذ المادة كاظم نايف كاظم اليساري       11/07/2018 15:52:07
Distance Measuring Techniques
1. Pacing:
• Imprecise
• Medium ( neither long or short ) .
• Pace length depends on legs opening.
• Accuracy ratios 1:100
? Note:- One pace = perimeter in m/ perimeter in pace
Dr. Randa Oqab Mujalli
2. Gunter’s Chain:
The Gunter’s chain used to survey North America was 66 ft long and
Dr. Randa Oqab Mujalli
3. Odometer:
• Fence lines abutting a road
• Distance to a traffic accident scene
• One rev =2?r
Then, n rev = d
then d = 2? r n
4. Tape:
Dr. Randa Oqab Mujalli
? Traditional method of measuring distance.
? Usually 30 m lengths.
? Available in steel and cloth.
Dr. Randa Oqab Mujalli
requires an
instrument with
crosshairs is designed so that the
divergence of the sights across the two
stadia crosshairs is 1.0 feet when the
instrument is 100 feet from the rod.
of 100.)
Dr. Randa Oqab Mujalli
When the top or bottom stadia hair
rod reading is obscured, a process
called 1/2 stadia can be used.
When 1/2 stadia is used the
elevation crosshair, and which ever