Bosch GRL 400 H Professional Original Instructions Manual page 23

OBJ_BUCH-1179-001.book Page 23 Thursday, August 5, 2010 10:04 AM
continuously lights up green), it automatically
starts in rotation operation. Now, check the
height of the laser beam with a reference point
and correct the height, if required.
When, after the shock-warning function has ac-
tuated, the function is not restarted by pressing
On/Off button 2, the laser 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 indicator goes out 3.
To switch on the shock-warning function, press
the On/Off button 2 for 3 seconds. The shock-
warning indicator 3 continuously lights up
green, and the shock-warning function is activat-
ed 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 influ-
ence. Especially temperature differences occur-
ring from the ground upward can divert the laser
beam.
The deviations play a role in excess of approx.
20 m measuring distance and can easily reach
two to four times the deviation 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 possible,
also set up the measuring tool in the centre of the
work area.
Bosch Power Tools
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 be-
fore starting your work.
A free measuring distance of 20 m on a firm sur-
face between two walls A and B is required for
the check. A reversal measurement must be car-
ried 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.
A
20 m
– After the levelling, mark the centre of the la-
ser beam on wall A (point I).
A
180°
– Rotate the measuring tool by 180°, allow it
to level in and mark the centre point of the la-
ser beam on the apposing wall B (point II).
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B
B
2 610 A13 330 | (5.8.10)