Nedo 460 812-613, Operating Instructions Manual

Page: 19 / 74

Theodolite ET-5 Operating Instructions 19
4 Preparation for Measurement EN
4.2 Aligning the instrument before measuring
1 Attach the theodolite to a tripod.
2
Pre-level the instrument with the help of the
adjustment screws and the circular bubble
installed in the tribrach.
3
Use the optical plummet* or plummet beam*
to align the instrument to the measuring point.
Repeat steps 2 and 3 until the bubble stays
centred in any position.
4
Rotate the theodolite according to the illus-
tration for fine levelling (the horizontal spirit
level should lie exactly between the adjust-
ment screws A and B. Align the instrument
using these two screws; the air bubble of the
horizontal spirit level has to be positioned
exactly in the middle of the two marks).
5
The theodolite is then rotated by 90°.
TIP:
Switch on the theodolite with the button
and set the angle indicator of the horizontal
circle to 0 with the button (display
0° 00’ 00”). Now turn the theodolite by exactly
90° and fix it securely.
The C setting screw EXCLUSIVELY must now
be used for levelling the theodolite. Repeat
steps 4 and 5 until the spirit level stays centred
in any position. It is recommended to check the
level by taking a rotation measurement (180°
rotation).
* Depending on the features: 460812-613 with optical plummet / 460814-613 with laser plummet.
OSet
ON/OFF