Working Advice For The Rotational Laser Level; Working Advice For The Laser Receiver - Bosch Professional GRL 400 H Manual Original

30 m
– Once levelling is complete, mark the centre of the laser
beam on the wall (point Ⅰ).
d
– Rotate the measuring tool 180° without changing its posi-
tion. Allow it to level in and mark the centre point of the
laser beam on the wall (point Ⅱ). Note that point Ⅱ should
preferably be positioned vertically 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 measur-
ing tool for the axis being measured.
Repeat the measuring process for the other axis. To do this,
turn the measuring tool by 90° before beginning the meas-
urement.
The maximum permitted deviation on the 30 m measuring
distance is as follows:
30 m × ±0.08 mm/m = ±2.4 mm. The discrepancy d
between points Ⅰ and Ⅱ must therefore amount to no more
than 4.8 mm for each of the two measuring processes.

Working advice for the rotational laser level

Only the centre of the laser line must be used for
u
marking. The width of the laser line changes depending
on the distance.
Working with the Laser Target Plate
The laser target plate (32) improves visibility of the laser
beam in unfavourable conditions and at greater distances.
The reflective surface of the laser target plate (32) improves
visibility of the laser line. The transparent surface enables
the laser line to be seen from behind the laser target plate.
Working with the Tripod (Accessory)
A tripod offers a stable, height-adjustable support surface
for measuring. Place the measuring tool with the 5/8" tripod
mount (9) on the thread of the tripod (25). Tighten the
measuring tool using the locking screw of the tripod.
On a tripod featuring a measuring scale on its extender, you
can set the height deviation straight away.
Bosch Power Tools
Roughly align the tripod before switching on the measuring
tool.
Working with the measuring rod (accessory)
(see figure D)
To check levels or apply slopes, it is recommended to use
the measuring rod (26) together with the laser receiver.
A relative measuring scale is incorporated at the top of the
measuring rod (26). You can preselect its zero at the bottom
on the extender. This enables you to read deviations from
the target height straight away.
Laser Goggles (Accessory)
The laser goggles filter out ambient light. This makes the
light of the laser appear brighter to the eye.
Do not use the laser goggles (accessory) as protective
u
180°
goggles. The laser goggles make the laser beam easier to
see; they do not protect you against laser radiation.
Do not use the laser goggles (accessory) as
u
sunglasses or while driving. The laser goggles do not
provide full UV protection and impair your ability to see
colours.

Working advice for the laser receiver

Aligning with the spirit level
The laser receiver can be aligned vertically (plumb line) with
the spirit level (20). If a laser receiver is mounted at an
angle, it will give incorrect measurements.
Marking
You can mark the position of the laser beam at the centre
mark (17) on the left and right of the laser receiver when the
beam hits the centre of the reception area (18).
The centre mark is located 45 mm away from the top edge of
the measuring tool.
When marking, take care to align the laser receiver so that it
is exactly vertical (with a horizontal laser beam) or horizontal
(with a vertical laser beam), as otherwise the marks are off-
set with respect to the laser beam.
Attaching using the holder (see figure B)
You can use the holder (29) to attach the laser receiver to a
measuring rod (26) (accessory) as well as to other auxiliary
tools with a width of up to 65 mm.
Screw the holder (29) to the mount (24) on the rear side of
the laser receiver with the fastening screw (28).
Loosen the rotary knob (27) on the holder, slide the holder
onto the measuring rod (26) and retighten the rotary
knob (27).
The centre line reference (30) on the holder is situated at
the same height as the centre marking (17) and can be used
for marking the laser beam.
Attaching using a magnet (see figure C)
If an attachment is not required to be especially secure, the
laser receiver can be attached to steel parts using the
magnets (16).
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1 609 92A 73P | (13.01.2022)