Bosch GRL 400 H Professional - Manual (Page 20)

20 | English
1 619 929 J22 | (27.6.11) Bosch Power Tools
f Do not subject the laser receiver to extreme tempera-
tures or variations in temperature. As an example, do not
leave it in vehicles for longer periods. In case of large varia-
tions in temperature, allow the laser receiver to adjust to the
ambient temperature before putting it into operation. In
case of extreme temperatures or variations in temperature,
the accuracy of the laser receiver can be impaired.
Position the laser receiver at least 50 cm away from the rota-
tional laser level. Position the laser receiver in such a manner
that the laser beam can reach the reception area 24.
Switching On and Off
f
A loud audio signal sounds when switching on the laser
receiver. “The A-weighted sound pressure level of the au-
dio signal is up to 95 dB(A) at a distance of 0.2 m.”
f Do not hold the laser receiver close to your ear! The
loud audio signal can cause hearing defects.
To switch on the laser receiver, press the On/Off button 19.
Two audio signals sound and all display indicators light up
briefly.
To switch off the laser receiver, press the On/Off button 19
again.
When no button is pressed on the laser receiver for approx.
10 minutes and when no laser beam reaches the reception ar-
ea 24 for 10 minutes, the laser receiver automatically switch-
es off in order to save the battery. The switching off is indicat-
ed by an audio signal.
Selecting the Setting of the Centre Indicator
With button 20, you can specify with which accuracy the po-
sition of the laser beam is indicated as central on the recep-
tion area:
– “Fine” adjustment, (indication f on the display),
– “Medium” adjustment, (indication a on the display).
An audio signal sounds when the accuracy setting is changed.
Whenever switching on the laser receiver, the accuracy level
“medium” is set.
Direction Indicators
The bottom g, centre e and top c indicators (both on the front
and rear side of the laser receiver) indicate the position of the
rotating laser beam in the reception area 24. Additionally, the
position can be indicated with an audio signal (see “Audio Sig-
nal for Indication of the Laser Beam”, page 20).
Laser receiver too low: When the laser beam runs through
the top half of the reception area 24, the bottom direction in-
dicator g appears on the display.
When the audio signal is switched on, a slow-beat signal
sounds.
Move the laser receiver upward in the direction of the arrow.
When approaching the centre mark 23, only the tip of the di-
rection indicator g is indicated.
Laser receiver too high: When the laser beam runs through
the bottom half of the reception area 24, the top direction in-
dicator c appears on the display.
When the audio signal is switched on, a fast-beat signal sounds.
Move the laser receiver downward in the direction of the ar-
row. When approaching the centre mark 23, only the tip of
the direction indicator c is indicated.
Laser receiver in centre position: When the laser beam runs
through the reception area 24 at the centre mark 23, the cen-
tre indicator e lights up. When the audio signal is switched on,
a continuous signal sounds.
Audio Signal for Indication of the Laser Beam
The position of the laser beam on the reception area 24 can
be indicated via an audio signal.
After the laser receiver has been switched on, the audio signal
is always switched off.
When switching on the audio signal, you can choose between
two volume levels.
To switch on the audio signal or change the volume level, push
the acoustic signal button 21 until the requested volume level
is indicated. At medium volume level, the audio signal indica-
tor d in the display flashes; at high volume level, the indicator
is continuously lit. When the audio signal is set to off, the indi-
cator goes out.
Automatic Levelling of the Rotational Laser Level
After switching on, the measuring tool checks the horizontal
position and automatically compensates irregularities within
the self-levelling range of approx. 8 % (5°).
When the measuring tool is inclined by more than 8 % after
switching on or after a position change, levelling in is no long-
er possible. In this case, the rotor is stopped, the laser flashes
and levelling indicator 1 continuously lights up red. Reposi-
tion the measuring tool and wait for it to re-level. Without re-
positioning, the laser is automatically switched off after
2 minutes and the measuring tool after 2 hours.
When the measuring tool is levelled in, it continuously checks
the horizontal position. Automatic re-levelling takes place af-
ter position changes. To avoid faulty measurements, the rotor
stops during the levelling process, the laser flashes and the
levelling indicator 1 flashes green.
Shock-warning Function
The measuring tool has a shock-warning function; after posi-
tion changes or shock to the measuring tool, or in case of
ground vibrations, it keeps the measuring tool from levelling
in at changed heights, and thus prevents vertical errors.
When factory set, the shock-warning function is activated af-
ter switching on the measuring tool (shock-warning indicator
3 lit). The shock warning is activated approx. 30 s after
switching on the measuring tool or switching on the shock-
warning function.
When the levelling-accuracy range is exceeded after a position
change of the measuring tool or when heavy ground vibrations
are detected, the shock-warning function is actuated: The rota-
tion is stopped, the laser flashes, the levelling indicator 1 goes
out and the shock-warning indicator 3 flashes red.
When the shock-warning function has actuated, briefly press
the On/Off button 2. The shock-warning function is restarted
and the measuring tool starts the levelling. As soon as the
measuring tool is levelled in (the levelling indicator 1 continu-
ously lights up green), it automatically starts in rotation oper-
ation. Now, check the height of the laser beam with a refer-
ence point and correct the height, if required.
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