Topcon AT-G6 User Manual

2) Next, focus on the target, by revolving the focusing
knob in either direction, as required.
3) Finally, use the fine horizontal knob for precise align-
ment of the target.
NOTE:
When precisely aligned, shift the eye to the left and right,
while looking
through the telescope eyepiece. There
sho uld be no deviations between the reticule cross-hairs
and the target, in this case. If there is parallax, which
means that either focusing is incomplete or that the
adjustment of the eyepiece was not done properly or
botlh. In any case, the focusing error must be eliminated
by carefully focusing or adjusting the eyepiece to the
user's eyesight.
OPERATIONS
1. Leveling or Determining the Differences in Elevation
The primary use of the Auto-Level is, of course, for
leveling. The purpose of leveling is , of course, to deter-
mine the elevation of a point or the difference in elevation
between points. Since the line of sight through the teles-
cope of the Auto-Level, which is properly set up, is
horizonta l, the differences in elevation is determined by
measuring
from th is horizontal line of sight.
Rod( 1) Rod( II)
Back sight Fo res igh t
bA
~ Ho = H•+•
HA _j_
l__ Temporary base level
1) Set up and level the instrument about halfway
between two points, say, A and B, if possible.
2)
Sight through the telescope on a leveling rod (I) held
on
top of point A and note the rod reading. (Say, the
line of sight is back towards the starting point, or the
"back sight", and the rod reading is bA.)
3) Next, sight through the telescope on a I eveling rod
(II) held on top of point B and also note the rod read-
ing. (The line of sight, of course, will now be in the
direction that the surveyor is go ing forward to and,
therefore, will be the "foresight", with the rod read-
ing, say, fB.)
4) Since both sights through the telescope are horizon-
tal, in this case, the difference in the rod readings is
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Topcon AT-G6 Specifications

General

Brand	Topcon
Model	AT-G6
Category	Measuring Instruments
Language	English