24
ENGLISH
[SK20GD]
B
C
1. Make a mark on the floor near the center of a room with 4 to 6 m walls.
2. Emit all vertical line beams.
3. Mark B and C near the center of the vertical line on the front and left wall.
B
C
D
A
B’
4. Align the vertical line on the front with C, and mark D near the center of the rear wall.
5. Likewise, mark A and B’.
6. The result is normal if the difference between B and B’ is within 3 mm.