Bosch Professional GLL 2 Manual Original página 17

OBJ_BUCH-1236-001.book Page 17 Thursday, May 20, 2010 12:18 PM
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 accuracy of the measuring tool each time be-
fore starting your work.
First, check both the height as well as the level-
ling accuracy of the horizontal laser line, then
the levelling accuracy of the vertical 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, a free measuring distance of
5 metres on a firm surface between two walls A
and B is required.
– Mount the measuring tool onto the holder or
a tripod, or place it on a firm and level sur-
face close to wall A. Switch the measuring
tool on.
A
5 m
– Direct the laser against the close wall A and
allow the measuring tool to level in. Mark the
centre of the point where the laser lines
cross each other on the wall (point I).
Bosch Power Tools
A
180°
– Turn the measuring tool by 180°, allow it to
level in and mark the cross point of the laser
lines on the opposite wall B (point II).
– Without turning the measuring tool, position
it close to wall B. Switch the measuring tool
on and allow it to level in.
A
– Align the height of the measuring tool (using
a tripod or by underlaying, if required) in
such a manner that the cross point of the
laser lines is projected against the previously
marked point II on the wall B.
B
English | 17
B
B
1 609 929 W91 | (20.5.10)