16
3) Mark point
a1
on the wall, in the middle of the
horizontal line at the left edge of the horizontal line
(see figure 5).
4) Turn the laser level counterclockwise until the right
edge of the horizontal line reaches near
a1
, mark a
point
a2
on the wall, in the middle of the horizontal line
(see figure 6).
1.5 m
a1
x
x a1
x a2
Figure # 5
approximately 5 m
Figure # 6
