Bosch GCL Professional 2-50 C Manual Original página 25

OBJ_BUCH-2870-004.book Page 25 Monday, February 27, 2017 3:47 PM
Levelling Accuracy
Influences on Accuracy
The ambient temperature has the greatest influence. Espe-
cially temperature differences occurring from the ground up-
ward 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.
First, check both the height as well as the levelling accuracy of
the horizontal laser line, then the levelling accuracy of the ver-
tical laser line.
Should the measuring tool exceed the maximum deviation
during one of the tests, please have it repaired by a Bosch af-
ter-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 onto a tripod or place it on a firm
and level surface close to wall A. Switch on the measuring
tool. Select cross-line operation with automatic levelling.
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).
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).
Bosch Power Tools
– 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.
A
d
– Without changing the height, turn around the measuring
tool by 180°. Direct it against the wall A in such a manner
B
that the vertical laser line runs through the already marked
point I. Allow the measuring tool to level in and mark the
cross point of the laser lines on the wall A (point III).
– The difference d of both marked points I and III on wall A
indicates the actual height deviation of the measuring tool.
The maximum permitted deviation d
follows:
d = double the distance between the walls x 0.3 mm/m
max
Example: If the distance between the walls is 5 m, the maxi-
mum deviation is
d = 2 x 5 m x 0.3 mm/m = 3 mm. The marks must there-
max
fore be maximum 3 mm apart.
B
English | 25
B
B
180°
can be calculated as
max
1 609 92A 2U5 | (27.2.17)