Automatic Levelling - Bosch Professional GLL 3-15 X Manual Original

OBJ_BUCH-2751-003.book Page 8 Monday, June 20, 2016 10:34 AM
8 | English
Deactivating the Automatic Shut-off
The measuring tool automatically switches itself off after
30 minutes of operation. To deactivate the automatic shut-
off, hold down either the vertical mode button 16 or the hori-
zontal mode button 17 for 3 seconds when switching on the
measuring tool. The laser lines will flash briefly after 3 sec-
onds if the automatic shut-off is deactivated.
 Do not leave the switched-on measuring tool unattend-
ed and switch the measuring tool off after use. Other
persons could be blinded by the laser beam.
To activate the automatic shut-off, switch the measuring tool
off and on again (without holding down a button).
Operation Modes (see figures B–D)
The horizontal and vertical modes can be switched on and off
independently of each other. All operation modes can be used
both with and without automatic levelling.
Horizontal operation
After it has been switched on, the measuring tool is in horizon-
tal mode and emits a horizontal laser line forwards.
To switch the horizontal laser line off or on, press the horizon-
tal mode 17 button.
Vertical mode and plumb point
The measuring tool has two vertical operation modes:
– vertical laser line forwards
– vertical laser line forwards and to the side
A plumb point is additionally projected downwards in all ver-
tical operation modes.
To switch the vertical mode on/off or to change the vertical
operation mode, press the vertical mode 16 button repeated-
ly until the required operation mode is reached.
If the measuring tool is mounted on the rotating platform 12,
you can precisely align the vertical laser lines to reference
points using the fine adjustment knob 11.

Automatic Levelling

Working with Automatic Levelling
Position the measuring tool on a level, firm support or attach
it to the rotating platform 12.
When working with automatic levelling, push the On/Off
switch 7 to the " On" position.
After switching on, the levelling function automatically com-
pensates irregularities within the self-levelling range of ±3°.
The levelling is finished as soon as the laser beams do not
move any more.
If automatic levelling is not possible, e.g. because the surface on
which the measuring tool stands deviates by more than 3° from
the horizontal plane, the laser lines will begin to flash quickly.
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 ±3°, the laser lines will light
up continuously.
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 laser lines with regard to
the reference points to avoid errors.
1 609 92A 301 | (20.6.16)
Working without Automatic Levelling
For work without automatic levelling, slide the on/off switch 7
to the " On" position. When automatic levelling is switched
off, the indicator 14 lights up red and the laser lines continu-
ously flash slowly.
When automatic levelling is switched off, you can hold the
measuring tool freely in your hand or place it on an inclined
surface. The laser lines no longer necessarily run perpendicu-
lar to each other.
Levelling Accuracy
Influences on Accuracy
The ambient temperature has the greatest influence. Espe-
cially temperature differences occurring from the ground
upward can divert the laser beam.
As thermal fluctuation is largest close to the ground, the
measuring tool, if possible, should be mounted on the tripod
19 and placed in the centre of the working area.
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 vertical
laser lines.
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, a free measuring distance of 5 m on a firm sur-
face between two walls A and B is required.
– Mount the measuring tool close to wall A on the rotating
platform or a tripod, or place it on a firm, flat surface.
Switch on the measuring tool in the mode with automatic
levelling. Switch on horizontal mode and any vertical oper-
ation mode.
A
5 m
– Direct the laser against the close wall A and allow the meas-
uring tool to level in. Mark the centre of the point where the
laser lines cross each other on the wall (point I).
B
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