Operating Modes; Automatic Levelling - Bosch GLL 3-80 Professional Manual Original

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14 | English
To activate the automatic shut-off, switch the measuring tool
off and then on again.
Deactivating the Signal Tone
After the measuring tool has been switched on, the audio
signal is always activated.
To deactivate or activate the audio signal, simultaneously
press the laser mode button 6 and the receiver mode button
4 and hold them down for at least 3 s.
The audio signal activation and deactivation are both con-
firmed by three short beeps.

Operating Modes

The measuring tool has several operating modes between
which you can switch at any time. These are for:
– Generating a horizontal laser plane,
– Generating a vertical laser plane,
– Generating two vertical laser planes,
– Generating a horizontal laser plane as well as two vertical
laser planes.
After you switch it on, the measuring tool generates a horizon-
tal laser plane. To change the operating mode, press the laser
mode button 6.
All operating modes can be selected both with and without

automatic levelling.

Receiver mode
Receiver mode must be activated to work with the laser re-
ceiver 16 – regardless of which operating mode is selected.
In receiver mode the laser lines flash at very high frequency,
enabling them to be detected by the laser receiver 16.
To switch on receiver mode, press button 4. Indicator 5 will
light up green.
When receiver mode is switched on, the laser lines are less
visible to the human eye. For this reason, switch receiver
mode off by pressing button 4 again to work without a laser
receiver. Indicator 5 will extinguish.
Automatic Levelling
Working with Automatic Levelling
Position the measuring tool on a level and firm support, attach
it to the holder 15 or to the tripod 23.
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 ±4°.
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 4°
from the horizontal plane, the laser lines begin to flash rapid-
ly. When the audio signal is activated, a fast-beat signal
sounds.
Set up the measuring tool in 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°, all laser beams light up
continuously and the audio signal is switched off.
1 609 92A 3PW | (27.4.17)
In case of ground vibrations or position changes during oper-
ation, the measuring tool is automatically levelled in again. To
avoid errors, check the position of the horizontal and vertical
laser line with regard to the reference points upon re-
levelling.
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 3 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.
Because the largest difference in temperature layers is close
to the ground, the measuring tool should always be mounted
on a tripod when measuring distances exceeding 20 m. If pos-
sible, also set up the measuring tool in the centre of the work
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 be-
ginning work.
Firstly, check the levelling accuracy of the horizontal laser line
and 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 Horizontal Levelling Accuracy of the Lateral
Axis
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 onto a tripod, or place it on a firm
and level surface close to wall A. Switch on the measuring
tool to operation with automatic levelling. Select the oper-
ating mode in which a horizontal laser plane as well as a
vertical laser plane in front of the measuring tool are gener-
ated.
A
5 m
B
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