User's Manual

4.5.6 Offset Measurement Mode

There are four kinds of Offset Measurement Modes:

z Angle Offset Measurement

z Distance Offset Measurement

z Plane Offset Measurement

z Column Offset Measurement

1) Angle Offset Measurement

This program is used to measure the point where it’s difficult to set prism. Place the prism

at the same horizontal distance from the instrument as that of point A0 to measure.

ƔWhen measuring coordinate of ground point A1(projection of point A0),set instrument

height and prism height.

ƔWhen measuring coordinate of point A0,set instrument height only(Prism height is set as

0).

ƔUnder angle offset measurement mode,there are two methods to set vertical angle:

1.Free vertical angle: vertical angle ranges from up-and-down movement of telescope.

2.Lock vertical angle:vertical angle is locked and can’t range from up-and-down

movement of telescope.

Thus,if collimate A0 with the first method, vertical angle ranges from up-and-down

movement of telescope,and meantime slope distance(SD) and elevation difference(VD)

will change too.But if collimate A0 with the second method,vertical angle is locked in the

direction where prism is located and can’t range from up-and-down movement of

telescope.