Bosch GPL 5 C Original Instructions Manual page 20

OBJ_BUCH-847-001.book Page 20 Friday, May 29, 2009 7:50 AM
20 | English
Working with Automatic Levelling
Position the measuring tool on a level and firm
support, attach it to the holder 13 or to the
tripod 17.
After switching on, the automatic levelling func-
tion automatically compensates irregularities
within the self-levelling range of ±4°. The level-
ling is finished as soon as the laser points or
laser lines do not move any more.
If automatic levelling is not possible, e.g. be-
cause the surface on which the measuring tool
stands deviates by more than 4° from the hori-
zontal plane, the laser lines begin to flash. When
the audio signal is activated, a fast-beat signal
sounds for maximum 30 s. This alarm is deacti-
vated within 10 s after switching on, in order to
allow adjustment of the measuring tool.
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 continu-
ously and the audio signal is switched off.
In case of ground vibrations or position changes
during operation, the measuring tool is automat-
ically levelled in again. To avoid errors by moving
the measuring tool, check the position of the
laser beams with regard to the reference points
upon re-levelling.
Levelling accuracy
Influences on Accuracy
The ambient temperature has the greatest influ-
ence. Especially temperature differences occur-
ring 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 a commercially available tripod
and placed in the centre of the working area.
Apart from exterior influences, device-specific
influences (such as heavy impact or falling down)
can lead to deviations. Therefore, check the accu-
racy of the measuring tool each time before start-
ing your work.
1 609 929 S06 | (29.5.09)
Should the measuring tool exceed the maximum
deviation during one of the tests, please have it
repaired by a Bosch after-sales service.
When the levelling accuracy of the horizontal
laser beams is within the maximum allowable
deviation, then the levelling accuracy of the
crossed laser lines (vertical axis) is thus also
checked.
Checking the Horizontal Levelling Accuracy
A free measuring distance of 20 m on a firm
surface between two walls A and B is required
for the check.
– Mount the measuring tool onto a tripod, or
place it on a firm and level surface close to
wall A. Switch the measuring tool on.
A
20 m
– Direct a horizontal point beam against (the
closer) wall A. Allow the measuring tool to
level in. Mark the centre of the laser beam on
the wall (point I).
A
180˚
– Turn the measuring tool around by 180°, allow
it to level in and mark the centre point of the
laser beam on the opposite wall B (point II).
B
B
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