Practical Advice - Bosch GCL 25 Professional Manual Original

A
– Align the height of the measuring tool (using the tripod or
by placing objects underneath as required) so that the
centre point of the laser beam exactly hits the previously
marked point Ⅱ on wall B.
A
d
– Turn the measuring tool 180° without adjusting the
height. Allow it to level in, then mark the centre point of
the laser beam on wall A (point Ⅲ). Ensure that point Ⅲ is
as vertical as possible above or below point Ⅰ.
– The discrepancy d between the two marked points Ⅰ and
Ⅲ on wall A reveals the actual height deviation of the
measuring tool along the longitudinal axis.
The maximum permitted deviation on the measuring dis-
tance of 2 × 20 m = 40 m is as follows:
40 m × ±0.3 mm/m = ±12 mm. The discrepancy d between
points Ⅰ and Ⅲ must therefore amount to no more than
12 mm.
Checking the Horizontal Levelling Accuracy of the
Transverse Axis
For this check, you will need a free measuring distance of
20 m on firm ground in front of a wall.
– Mount the measuring tool 20 m from the wall on the
holder (15) or a tripod, or place it on a firm, level surface.
Switch on the measuring tool and select five-point mode
with automatic levelling.
Bosch Power Tools
B
– Aim one of the two side laser beams that run along the
transverse axis of the measuring tool at the wall. Allow the
measuring tool to level in. Mark the centre of the laser
point on the wall (point Ⅰ).
B
180°
– Turn the measuring tool 180° without adjusting the
height. Allow it to level in, then mark the centre point of
the other side laser beam on the wall (point Ⅱ). Ensure
that point Ⅱ is as vertical as possible above or below
point Ⅰ.
– The discrepancy d between the two marked points Ⅰ
and Ⅱ on the wall reveals the actual height deviation of the
measuring tool along the transverse axis.
The maximum permitted deviation on the measuring dis-
tance of 2 × 20 m = 40 m is as follows:
40 m × ±0.3 mm/m = ±12 mm. The discrepancy d between
points Ⅰ and Ⅱ must therefore amount to no more than
12 mm.

Practical Advice

Only the centre of the laser point or laser line must be
u
used for marking. The size of the laser point/the width of
the laser line changes depending on the distance.
Working with the Tripod (Accessory)
A tripod offers a stable, height-adjustable support surface
for measuring. Place the measuring tool with the 1/4" tripod
mount (6) on the thread of the tripod (16) or a conventional
camera tripod. Use the 5/8" tripod mount (5) to secure the
measuring tool on a conventional building tripod. Tighten the
measuring tool using the locking screw of the tripod.
2 0
m
d
1 609 92A 4HF | (20.08.2018)
English | 15
180°