Operating Mode; Automatic Levelling; Accuracy Check Of The Measuring Tool - Bosch GLL 3 X Professional Notice Originale

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Operating mode

ture (1). Both vertical laser lines run at a 90°
angle to each other.
Horizontal operation (see figure D): The
measuring tool generates a horizontal laser
line out of the front laser outlet aperture (1).
Vertical operation (see figure E): The meas-
uring tool generates a vertical laser line out
of the front laser outlet aperture (1).
All operating modes can be selected with both automatic lev-
elling or the pendulum lock.

Automatic Levelling

Working with automatic levelling (see figures A–E)
Position the measuring tool on a level, firm support or attach
it to a tripod (14).
To work with automatic levelling, push the pendulum lock
switch (4) to the position. The status indicator (2) lights
up green (symbol /green).
The automatic levelling function automatically compensates
irregularities within the self-levelling range of ±4°. The level-
ling is finished as soon as the laser lines stop moving.
If automatic levelling is not possible, e.g. because the sur-
face on which the measuring tool is standing deviates by
more than 4° from the horizontal plane, the automatic status
indicator (2) lights up red, the laser lines flash and an audio
signal sounds.
If this is the case, set up the measuring tool in a level position
and wait for the self-levelling to take place. As soon as the
measuring tool is within the self-levelling range of ±4°, the
laser lines light up continuously, the status indicator (2)
lights up green and the audio signal is switched off.
It is not possible to work with automatic levelling outside the
self-levelling range of ±4°, as the levelling accuracy of the
laser beams cannot be guaranteed and it cannot be guaran-
teed that the laser beams are perpendicular.
In case of ground vibrations or position changes during oper-
ation, the measuring tool is automatically levelled again.
Upon re-levelling, check the position of the horizontal or ver-
tical laser line with regard to the reference points to avoid er-
rors by moving the measuring tool.
Working with a pendulum lock (see figure F)
To work with a pendulum lock, push the pendulum lock
switch (4) to the position. The status indicator (2) lights
up red (symbol /red).
For work with the pendulum lock, the automatic levelling is
switched off. You can hold the measuring tool freely in your
hand or place it on a sloping surface. This means that the
laser lines are no longer levelled and no longer necessarily
run perpendicular to one another.
1 609 92A 58S | (09.06.2020)

Accuracy Check of the Measuring Tool

Influences on Accuracy
The largest influence is exerted by the ambient temperature.
In particular, temperature differences that occur from the
ground upwards can refract the laser beam.
Since the temperature stratification is greatest at ground
level, you should mount the measuring tool on a tripod and
position it in the centre of the work surface, wherever this is
possible.
In addition to external influences, device-specific influences
(e.g. falls or heavy impacts) can also lead to deviations. For
this reason, check the levelling accuracy each time before
beginning work.
First check the height accuracy and levelling accuracy of the
horizontal laser line, then the levelling accuracy of the ver-
tical laser line.
Should the measuring tool exceed the maximum deviation
during one of the tests, please have it repaired by a Bosch
after-sales service.
Checking the Height Accuracy of the Horizontal Line
For this check, you will need a free measuring distance of
5 m on firm ground between two walls (designated A and B).
– Mount the measuring tool close to wall A on a tripod, or
place it on a firm, level surface. Switch on the measuring
tool. Select cross-line mode with automatic levelling.
A
5 m
– Aim the laser at the closer wall A and allow the measuring
tool to level in. Mark the middle of the point at which the
laser lines cross on the wall (point I).
A
180°
– Turn the measuring tool 180°, allow it to level in and mark
the point where the laser lines cross on the opposite wall
B (point Ⅱ).
– Position the measuring tool – without rotating it – close to
wall B, switch it on and allow it to level in.
B
B
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