Bosch BL 40 VHR Professional Bedienungsanleitung Seite 18

bl40_bu1_1609929E39_t.fm Seite 4 Dienstag, 14. Februar 2006 3:14 15
Levelling and Alignment of the
Construction Laser
Horizontal Alignment/Aligning the Plumb Beam
A
Switch on the construction laser and align with the bubble level (1) 6 by
turning the adjustment knob (1) 8 to the right until level. The bubble level
(3) 12 is aligned by turning the adjustment knob (2) 10 to the right. When
the bubble levels 6 and 12 are aligned, the unit is level and ready for op-
eration.
Vertical Alignment
B
Switch on the construction laser and, as shown in the illustration, align the
bubble level (2) 7 by rotating the adjustment knob (2) 10 up or down until
level.
Note: When working over an extended period of time, check the position
of the level bubbles regularly.
Levelling Accuracy
Influences on the Accuracy

The largest influence is exerted by the ambient temperature.
Especially temperature differences occurring from the ground
upwards can deflect the laser beam.
The deviations are significant at a distance of approx. 20 m and can dou-
ble or quadruple at a distance of 100 m.
Since the temperature gradient near the floor is the greatest, a tripod
should always be used when working at distances over 20 m. In addi-
tion, the unit should always be set up in the middle of the working area.
Accuracy Check of the Unit
In addition to external influences, deviations can also be caused by influ-
ences within the unit itself. For this reason, the accuracy should be
checked from time to time.
Procedure
– A free measuring path of 20 m is required.
– A transit measurement on firm ground must be performed over both
X and Y axes (four measurements).
– Place the unit in the horizontal position on a solid, level base and
switch on.
– After levelling, mark the laser point (centre of the point) at a convenient
position, for example, on a wall.
– Then rotate the unit by approx. 90° without lifting it, i.e., without
changing its height.
– Now turn back the prism cap 1, realign with the bubble levels and
mark again. Repeat this procedure in two additional 90° steps. The
heights of all four measurements are now marked at the same posi-
tion on the wall.
1 609 929 E39 • (06.02) T
English–4