©2010 Johnson Level & Tool - Rev. 1
9
Accuracy Self-Check - Horizontal Laser (40-6675 only)
1. Set the instrument on a level surface such as a flat head tripod
centered between two walls (marked 1 & 2) approximately 25 feet
apart. (See fig. 1).
2. Point the instrument directly at wall 1. Turn the laser on and mark the the
beam as point A.
3. Turn the instrument 180 degrees so that the laser is pointed directly at wall
2. Turn the laser and mark the beam as point B.
4. Move the instrument and the tripod so the laser is positioned approximately
2 feet away from wall 1 (see fig. 2). Level the tripod and position the
instrument on the tripod facing wall 1. Turn the laser on and mark the the
beam as point C.
5. Turn the laser off and rotate the laser 180 degrees so that it is
facing directly to wall 2.
6. Turn on the laser and mark the beam
as point D.
7. Measure the distance between
points A & C.
8. Measure the distance between
points B & D.
9. If the difference between points
A & C and points B & D are less
than 1/16”, your instrument is within
its tolerance.
10. If it is greater than 1/16”, your unit
will need to be recalibrated.
Wall 1
Wall 2
Fig 1
Fig 2
25 ft.
(7.6m)
25 ft.
(7.6m)
48 ft.
(14.6m)
4043H_Manuals 10/29/10 9:31 AM Page 9
