chain lines which go out of alignment short measurements from chain line sets of minor instruments in chain surveying ties or check lines which are perpendicular to chain line
Answer Discuss in Comment
both chaining and ranging ranging but not chaining chaining but not ranging neither chaining nor ranging
is used at the time of standardising the tape makes the correction due to sag equal to zero makes the correction due to pull equal to zero neutralizes the effect due to pull and sag
steel tape cross staff line ranger optical square
30° 45° 60° 90°
difference in principle of working that optical square is more accurate than prism square that no adjustment is required in a prism square since the angle between the reflecting surfaces cannot be changed all of the above
any angle either 45° or 90° 45° only 90° only
degree of accuracy required method of setting out the perpendiculars and nature of ground scale of plotting all of the above
all involve equal measurement on the ground method of perpendicular offsets method of oblique offsets method of ties
is easier to handle can be easily repaired in the field is lighter than chain is practically inextensible and is not liable to kinks when in use
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