Bosch GLL 2-20 Professional Manual Original página 11

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
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 × ±0.4 mm/m = ±4 mm. The discrepancy d between
points Ⅰ and Ⅱ must therefore amount to no more than 4 mm.
Checking the Level Accuracy of the Vertical Line
For this check, you will need a door opening (on solid
ground) which has at least 2.5 m of space either side of the
door.
– Place the measuring tool 2.5 m away from the door open-
ing on a firm, flat surface (not on a tripod). Select vertical
mode with automatic levelling. Aim the vertical laser line
at the door opening and allow the measuring tool to level
in.
Bosch Power Tools
B
– Mark the centre of the vertical laser line on the floor of the
B
door opening (point Ⅰ), 5 m away on the other side of the
180°
door opening (point Ⅱ) and on the upper edge of the door
opening (point Ⅲ).
– Rotate the measuring tool 180° and position it on the
other side of the door opening, directly behind point Ⅱ.
Allow the measuring tool to level in and align the vertical
laser line in such a way that its centre passes through
points Ⅰ and Ⅱ exactly.
– Mark the centre of the laser line on the upper edge of the
door opening as point Ⅳ.
– The discrepancy d between the two marked points Ⅲ and
Ⅳ reveals the actual vertical deviation of the measuring
tool.
– Measure the height of the door opening.
You can calculate the maximum permitted deviation as fol-
lows:
Doubled height of the door opening × 0.4 mm/m
Example: At a door opening height of 2 m, the maximum de-
viation amounts to
2 × 2 m × ±0.4 mm/m = ±1.6 mm. The points Ⅲ and Ⅳ
must therefore be no further than 1.6 mm from each other.
English | 11
1 609 92A 4HK | (08.10.2020)