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9. Offset Measurement
Offset measurement are performed in order to find a point where a target cannot be
installed directly or to find the distance and angle to a point which cannot be sighted.
It is possible to find the distance and angle to a point you wish to measure (target point)
by installing the target at a location (offset point) a little distance from the target point and
measuring the distance and angle from the surveying point to the offset point.
The target point could be found in the following three ways.
9.1 Single-distance Offset Measurement
Finding a point by entering the horizontal distance from the target point to the offset
point.
When the offset point is positioned to the left or right of the target point, make sure the
angle formed by lines connecting the offset point to the target point and to the instrument
station is almost
90
°
.
When the offset point is positioned in front of or behind the target point, installs the offset
point on a line linking the instrument station with the target point.
【
Procedure of single-distance offset measurement
】
1. Set the offset point close to the target point and
measure the distance between them, then set up a
prism on the offset point.
2. Aim at the offset point and press F1: [
MEAS
] to
measure the distance at P1 in measure mode.
Target point
Offset point
(Target)
Instrument station
Menu P1
1.Coordinate
2.Stake out
3.Area
4.Offset
5.MLM
6.REM
7.Resection
