Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Difference between upper and lower stadia reading gives __________
stadia slope
stadia coordinate
stadia intercept
staff intercept
stadia intercept
In tacheometry, the difference between the upper stadia hair reading and the lower stadia hair reading observed on a vertical leveling staff is known as the stadia intercept (or staff intercept). It is denoted by the variable S, calculated as S=Upper┬аReadingтИТLower┬аReading. This value is directly proportional to the distance between the instrument station and the staff.
In tacheometry, the difference between the upper stadia hair reading and the lower stadia hair reading observed on a vertical leveling staff is known as the stadia intercept (or staff intercept). It is denoted by the variable S, calculated as S=Upper┬аReadingтИТLower┬аReading. This value is directly proportional to the distance between the instrument station and the staff.
S=ReadingupperтАЛтИТReadinglowerтАЛ тАФ Stadia Intercept equation
D=KтЛЕS+C тАФ Tacheometric Distance formula for horizontal sight
Tacheometry relies on the principle of similar triangles. When sighting through a telescope equipped with a stadia diaphragm, the fixed vertical spacing between the outer horizontal hairs subtends a proportional height on a distant staff. As the staff is moved farther away, the intercepts observed between the upper and lower stadia lines increase linearly with horizontal distance.
The diaphragm of a tacheometer contains three horizontal cross-hairs: top, central (axial), and bottom.
Multiplying constant K=ifтАЛ is typically 100 for standard instruments.
Additive constant C=(f+c) is typically 0 for modern or anallatic lens systems.
Eliminates the need for physical chaining or taping over rough terrain.
Allows rapid determination of both horizontal distances and vertical elevations.
Sight distances are limited by staff visibility and optical magnification.
Reading errors on the staff scale directly impact calculated horizontal distances.
Topographical surveys in hilly, steep, or broken ground where chaining is difficult.
Contour mapping and location surveys for roads, railways, and reservoirs.
The central axial reading gives the height of the line of sight on the staff.
Option A (stadia slope) refers to the angle of inclination of the telescope line of sight.
Option B (stadia coordinate) is not a standard surveying parameter term.
Option D (staff intercept) is sometimes used synonymously, but 'stadia intercept' precisely describes the distance measured between stadia hair readings on the reticule.
C is correct тАФ The difference between upper and lower stadia hair readings on a leveling staff defines the stadia intercept.
For horizontal line of sight, D=KS+C; if an anallatic lens is used, C=0, simplifying the relation to D=100S.