Accuracy Check Of The Measuring Tool - Bosch GLL 3-15 X Professional Manual Original

Accuracy Check of the Measuring Tool

Influences on Accuracy
The largest influence is exerted by the ambient temperature.
In particular, temperature differences that occur from the
ground upwards can refract the laser beam.
Since the temperature stratification is greatest at ground
level, you should mount the measuring tool on a tripod and
position it in the centre of the work surface, wherever this is
possible.
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
beginning work.
First check the height accuracy and 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
after-sales service.
Checking the Height Accuracy of the Horizontal Line
For this check, you will need a free measuring distance of
5 m on firm ground between two walls (designated A and B).
– Mount the measuring tool close to wall A on the rotating
platform (12) or a tripod (24), or place it on a firm, flat
surface. Switch on the measuring tool in the mode with
automatic levelling. Switch on horizontal mode and ver-
tical mode with a laser line forwards.
A
5 m
– Aim the laser at the closer wall A and allow the measuring
tool to level in. Mark the middle of the point at which the
laser lines cross on the wall (point I).
A
180°
– Turn the measuring tool 180°, allow it to level in and mark
the point where the laser lines cross on the opposite wall
B (point Ⅱ).
Bosch Power Tools
– Position the measuring tool – without rotating it – close to
wall B, switch it on and allow it to level in.
A
– Align the height of the measuring tool (using the tripod or
by placing objects underneath as required) so that the
point where the laser lines cross exactly hits the previ-
ously marked point Ⅱ on wall B.
A
d
– Turn the measuring tool 180° without adjusting the
height. Aim it at wall A such that the vertical laser line runs
B
through the already marked point Ⅰ. Allow the measuring
tool to level in and mark the point where the laser lines
cross on wall A (point Ⅲ).
– The discrepancy d between the two marked points Ⅰ and
Ⅲ on wall A reveals the actual height deviation of the
measuring tool.
The maximum permitted deviation on the measuring dis-
tance of 2 × 5 m = 10 m is as follows:
10 m × ±0.2 mm/m = ±2 mm. The discrepancy d between
points Ⅰ and Ⅲ must therefore amount to no more than
2 mm.
Checking the Level Accuracy of the Horizontal Line
For this check, you will need a free area of 5 × 5 m.
– Mount the measuring tool in the middle between walls A
B
and B on the rotating platform (12) or a tripod (24), or
place it on a firm, flat surface. Switch on the measuring
tool in the mode with automatic levelling. Switch on hori-
zontal mode and allow the measuring tool to level in.
English | 9
B
B
180°
1 609 92A 4HL | (27.11.2020)