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CHECKING ACCURACY – VERTICAL BEAMS (FIG. 7A, 7B)
Checking the vertical (plumb) calibration of the laser can be most 
accurately done when there is asubstantial amount of vertical height 
available, ideally 9 m (30'), with one person on the floor positioning 
the laser and another person near aceiling to mark the position of the 
beam. It is important to conduct acalibration check using adistance 
no shorter than the distance of the applications for which the tool will 
be used.
  TABLE 3 
  Ceiling   Allowable Distance  
  Height  Between Marks
  2.5 m (8')  1.5 mm (1/16")
  3.0 m (10')  2.0 mm (3/32")
  4.0 m (14')  2.5 mm (1/8")
  6.0 m (20')  4.0 mm (5/32")
  9.0 m (30')  6.0 mm (1/4")
  1. Place the laser on the floor and turn on both vertical beams.
  2. Mark the position where the beams cross on the floor (F) and also 
on the ceiling (G). Always mark the centre of the beams’ thickness.
  3. Rotate the laser 180 degrees, and reposition it so the beam 
crossing is exactly on the original mark on the floor.
  4. Mark the position where the beams cross on the ceiling (H).
  5. Measure the distance between the two ceiling marks. If the 
measurement is greater than the values shown in Table 3, the laser 
must be serviced at an authorised service centre.
CHECKING 90º ACCURACY BETWEEN VERTICAL BEAMS (FIG. 8A–8C)
Checking 90º accuracy requires an open floor area at least 10 m x 5 m 
(33' x 18'). Refer to the graphic for the position of the DW089 at each 
step and for the location of the marks made at each step. Always mark 
the centre of the beam'sthickness.
DW089_DW089CG - User Manual - NA - May 2018.indd   20 5/25/2018   10:40:48 AM