-7-
of the circular bubble vial.
Any remaining deviation of the instrument
to the horizontal plane following the
balancing of the circular bubble vial
is compensated by means of the
compensator.
While working, regularly check (e.g. by
viewing through the bubble vial mirror
3
)
whether the air bubble is still in the centre
of the circular bubble vial.
Setting Up Over a Point
!
WARNING
Never use force on any
parts of the instrument.
All moving parts will turn freely and easily
by hand.
Hang the plumb bob
19
, attach cord to
the plumb bob hook of the tripod.
Move the tripod and instrument over the
approximate point. (Be sure the tripod
is set up firmly again. Loosen leveling
screws and shift the instrument laterally
until the instrument is positioned directly
over the point. Align the instrument again.
Focusing the Telescope
Remove the lens cap from the objective
lens
1
.
Direct the telescope against a bright
object or hold a white sheet of paper in
front of the objective lens
1
.
Turn the eyepiece
5
until the crosshair
appears sharp and deep black.
B
A
100’
(30 m)
a
1
b
d
1
B
A
3’
(1 m)
a
2
b
2
d
350
340
0
10
50
40
30
a
2
– d = b
2
a
1
– b
1
= d
Direct the telescope towards the levelling
rod, if required with help of the optical
peep sight
2
.
Turn the focusing knob
15
until the
graduation field of the levelling rod
appears sharp. Align the crosshair exactly
with the center of the leveling rod by
turning the horizontal drive screw
14
.
When the telescope is correctly focussed,
the crosshair and the image of the
levelling rod must remain aligned when
moving your eye behind the eyepiece.
Measuring Functions
Always set up the levelling rod exactly
vertical. Direct the aligned and focused
measuring tool against the levelling rod in
such a manner that the crosshair faces
centrally against the levelling rod.
Reading the Height
Read off the height of the levelling rod at
the centre line of the crosshair.
B
A
100’
(30 m)
a
1
b
d
1
B
A
3’
(1 m)
a
2
b
2
d
350
340
0
10
50
40
30
a
2
– d = b
2
a
1
– b
1
= d
Height measured in the figure: 2.0 ft
(1.195 m).
Measuring a Distance
Centre the measuring tool above the
point from which on the distance is to be
measured.
Read off the height of the levelling rod at
the top and bottom stadia lines. Multiply
the difference of both heights by 100 to
receive the distance from the measuring
tool to the levelling rod.
B
A
100’
(30 m)
a
1
b
d
1
B
A
3’
(1 m)
a
2
b
2
d
350
340
0
10
50
40
30
a
2
– d = b
2
a
1
– b
1
= d
Distance measured in the figure:
(1.347m – 1.042m) x 100 = 30.5 m.
