Bosch GPL 3 Professional Manual Original página 14

OBJ_BUCH-807-002.book Page 14 Tuesday, September 30, 2008 1:13 PM
14 | English
Levelling Accuracy
Influences on Accuracy
The ambient temperature has the greatest in-
fluence. Especially 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 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
before starting your work.
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
A free measuring distance of 20 m on a firm sur-
face between two walls A and B is required for
the check.
– 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
20 m
– Direct the horizontal laser beam against the
close wall A and allow the measuring tool to
level in. Mark the centre of the laser beam on
the wall (point I).
1 609 929 S08 | (30.9.08)
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).
– 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
the tripod or by underlaying, if required) in
such a manner that the centre point of the
laser beam is projected exactly against the
B previously marked point II on wall B.
B
B
Bosch Power Tools