Starting Operation Of The Laser Receiver; Switching On/Off; Direction Indicators - Bosch GRL 400 H Professional Manual Original

22 | English
Do not direct the laser beam at persons or animals and
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do not stare into the laser beam yourself (even from a
distance).
The measuring tool immediately starts automatic levelling.
During levelling, the status indicator (5) flashes green, the
laser does not rotate and flashes.
The measuring tool is levelled in as soon as the status
indicator (5) lights up green continuously and the laser lights
up continuously. After levelling is completed, the measuring
tool automatically starts in rotational operation.
Never leave the measuring tool unattended when
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switched on, and ensure the measuring tool is
switched off after use. Others may be blinded by the
laser beam.
The measuring tool exclusively operates with fixed rotational
speed in rotational operation, which is also suitable for use
of a laser receiver.
When factory set, the shock-warning function is automatic-
ally switched on and the shock-warning function
indicator (3) lights up green.
To switch off the measuring tool, briefly press the on/off
button (4). When the shock warning has actuated (the
shock-warning function indicator (3) flashes red), briefly
press the on/off button once to restart the shock-warning
function and then press it briefly again to switch off the
measuring tool.
To save the non-rechargeable/rechargeable batteries, the
measuring tool is automatically switched off when not within
the self-levelling range for more than 2 hours or when the
shock warning is actuated for more than 2 hours. Reposition
the measuring tool and switch on again.

Starting operation of the laser receiver

Setting up the laser receiver (see figure A)
Place the laser receiver at least 0.5 m away from the rotary
laser. For rotary lasers with multiple operating modes, select
the horizontal or vertical operation with the highest rota-
tional speed.
Position the laser receiver so that the laser beam can reach
the reception area (24). Align it so that the laser beam runs
straight through the reception area (as shown in the figure).

Switching On/Off

A loud audio signal sounds when switching on the
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laser receiver. Therefore, keep the laser receiver
away from your ear or other persons when switching it
on. The loud sound can damage hearing.
To switch on the laser receiver, press the on/off
button (19). All display indicators light up briefly and two
audio signals sound.
After the laser receiver is switched on, the measuring accur-
acy is always set to "medium" and the audio signal is always
switched off.
To switch off the laser receiver, press the on/off
button (19) again.
If no button on the laser receiver is pressed for approx.
10 min and no laser beam reaches the reception area (24)
1 609 92A 5S3 | (09.09.2020)
for 10 min, the laser receiver will automatically switch itself
off to preserve battery life. An audio signal indicates when
the laser receiver is switching off.
Selecting the setting of the centre line indicator
You can use the button adjusting the reception
accuracy (20) to specify the accuracy with which the posi-
tion of the laser beam is indicated as "centred" on the recep-
tion area:
– Measuring accuracy "fine" (indicator (f) on the display),
– Measuring accuracy "medium" (indicator (a) on the dis-
play).
An audio signal sounds every time the accuracy setting is
changed.

Direction indicators

The position of the laser beam in the reception area (24) is
indicated as follows:
– On the display (25) on the front and rear of the laser re-
ceiver by means of the "laser beam below centre line" dir-
ection indicator (c), the "laser beam above centre line"
direction indicator (g) and the centre line indicator (e),
– By an audio signal (optional) (see "Laser Beam Indicator
Audio Signal", page 22).
Laser receiver too low: If the laser beam hits the upper half
of the reception area (24), then the "laser beam above
centre line" direction indicator (g) appears in the display.
If the audio signal is switched on, a slow-beat signal sounds.
Move the laser receiver upwards in the direction of the ar-
row. When the laser beam is close to the centre line, only the
tip of the "laser beam above centre line" direction
indicator (g) is shown.
Laser receiver too high: If the laser beam hits the lower half
of the reception area (24), then the "laser beam below
centre line" direction indicator (c) appears in the display.
If the audio signal is switched on, a fast-beat signal sounds.
Move the laser receiver downwards in the direction of the ar-
row. When the laser beam is close to the centre line, only the
tip of the "laser beam below centre line" direction
indicator (c) is shown.
Laser receiver centred: If the laser beam hits the reception
area (24) at the height of the centre mark (23), then the
centre line indicator (e) appears in the display.
If the audio signal is switched on, a continuous signal
sounds.
Laser Beam Indicator Audio Signal
The position of the laser beam on the reception area (24)
can also be indicated by an audio signal.
You can select two different volumes for the audio signal.
To switch on the audio signal or change the volume level,
push the audio signal button (21) until the required volume
level is indicated on the display. At medium volume, the au-
dio signal indicator (d) flashes on the display; at high
volume, the indicator is continuously lit. When the audio sig-
nal is switched off, the indicator goes out.
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