Civil Engineering - Surveying - Discussion
Discussion Forum : Surveying - Section 6 (Q.No. 35)
35.
A dumpy level was set up at mid-point between pegs A and B, 80 m apart and the staff readings were 1.32 and 1.56. When the level was set up at a point 10 m from A on BA produced, the staff readings obtained at A and B were 1.11 and 1.39. The correct staff reading from this set up at S should be
Discussion:
13 comments Page 2 of 2.
Ishfaq ahmad sofi said:
8 years ago
For mid point station { 1.56-1.32=.24} for second station {1.39-1.11=.28}.
The difference in reading shows collimation error , which is .28-.24=.04,
.04 is collimation error in 80 m.therefore in 90m = (.04/80)*90=.045,
Now correct reading at B = 1.39 - .045 = 1.345.
The difference in reading shows collimation error , which is .28-.24=.04,
.04 is collimation error in 80 m.therefore in 90m = (.04/80)*90=.045,
Now correct reading at B = 1.39 - .045 = 1.345.
(5)
Aamir said:
9 years ago
The difference in level b/w A and B:1.56-1.32=.24.
Apparent difference = 1.39-1.11 = .28,
True difference = 1.11 + .24 = 1.35,
Collimation error in 80m = 1.39-1.35 = 0.04.
Collimation error in 90m=(.04 * 90)÷80 = .045m.
Nd correction =.045m.
Correct staff reading on B=1.390-.045=1.345m.
Apparent difference = 1.39-1.11 = .28,
True difference = 1.11 + .24 = 1.35,
Collimation error in 80m = 1.39-1.35 = 0.04.
Collimation error in 90m=(.04 * 90)÷80 = .045m.
Nd correction =.045m.
Correct staff reading on B=1.390-.045=1.345m.
Satish said:
9 years ago
How to get this answer? Please explain it.
(1)
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