Question
Download Solution PDFCalculate the horizontal distance of a point from the instrument, if the staff intercept is 2.5 m. The micrometer reading of the drum of the diaphragm is 3.2 and the micrometer screw has 100 threads in 1 cm. The focal length of the objective glass is 200 mm and the distance of the instrument axis from the centre of the object glass is 180 mm.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept:
Slope, temperature, and tension corrections are required in chain surveying, not in Tacheometric surveying.
In Method of Tacheometry
In this figure, the Line of sight is horizontal and staff is held truly vertical.
Tacheometric distance formula
\(D=\left(\dfrac{f}{i}\right)s + (f+d) \)
D = KS + C
Where,
K is (f/i) → called a multiplying constant
C is (f + d) → called an additive constant
As
f = focal length of the lens, i = stadia hair interval
Given, f = 200 mm = 0.2 m
d = 180 mm = 0.18 m, s = 2.5 m
\({\rm{i}} = \frac{{3.2}}{{1000}} × 100 = 0.32\) mm
k = \(\frac{f}{i}\)
⇒ k = 200/0.32 = 625
C = f + d
C = 0.2 + 0.18 = 0.38 m
s = 2500 mm = 2.5 m
D = 625 × 2.5 + 0.28 = 1562.8 m
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