Bosch GRL 400 H Professional - Manual (Page 21)

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Bosch Power Tools 1 619 929 J22 | (27.6.11)
When, after the shock-warning function has actuated, the
function is not restarted by pressing On/Off button 2, the la-
ser is automatically switched off after 2 minutes and the
measuring tool after 2 hours.
To switch off the shock-warning function, press the On/Off
button 2 for 3 seconds. When the shock-warning function has
actuated (shock-warning indicator 3 flashes red), firstly press
the On/Off button briefly, and then again for 3 seconds. When
the shock-warning function is shut off, the shock-warning in-
dicator goes out 3.
To switch on the shock-warning function, press the On/Off
button 2 for 3 seconds. The shock-warning indicator 3 contin-
uously lights up green, and the shock-warning function is acti-
vated after 30 seconds.
The shock-warning function setting is stored when switching
off the measuring tool.
Levelling Accuracy of the Rotational Laser Level
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.
The deviations play a role in excess of approx. 20 m measur-
ing distance and can easily reach two to four times the devia-
tion at 100 m.
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.
Accuracy Check of the Measuring Tool
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.
A free measuring distance of 20 m on a firm surface between
two walls A and B is required for the check. A reversal meas-
urement must be carried out over both axes X and Y (each
positive and negative; 4 complete measurements).
– Mount the measuring tool onto a tripod, or place it on a firm
and level surface close to wall A. Switch the measuring tool
on.
– After the levelling, mark the centre of the laser beam on
wall A (point I).
– Rotate the measuring tool by 180°, allow it to level in and
mark the centre point of the laser beam on the apposing
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.
– Align the height of the measuring tool (using the tripod or
by propping), so that the centre of the laser beam runs ex-
actly against the previously marked point II on wall B.
– Rotate the measuring tool by 180° without changing the
height. Allow it to level in and mark the centre point of the
laser beam on wall A (point III). Take care that point III is
as vertical as possible above or below point I.
– The difference d of both marked points I and III on wall A
amounts to the actual deviation of the measuring tool for
the measured axis.
Repeat the measuring procedure for the other three axes. For
this, turn the measuring tool prior to each measuring proce-
dure by 90°.
On the measuring section of 2 x 20 m = 40 m, the maximum
allowable deviation is:
40 m x ±0.08 mm/m = ±3.2 mm.
Consequently, the difference d between points I and III for
each of the four individual measurements may not exceed
3.2 mm max.
A B
20 m
A B
180°
A B
A B
180°
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