8369H-All_Manuals 10/3/14 1:57 PM Page 12
Horizontal Accuracy (longitudinal)
1. Set up two grade rods which are 15 feet
away from each other as seen to the right
(or two parallel walls which are more than
15 feet away from each other.)
2. Mount the laser on a tripod 15 feet away
from the left grade rod, level out the bubble
by adjusting the tripod.
3. Power on the laser, mark the cross dot of V1 line and H line on the
grade rod as "C".
4. Rotate the tripod 180º, mark the cross dot of V2 and H as "D".
5. Move the tripod 15 feet away from the right grade rod. Line up the
cross dot with point "D" by elevating the tripod.
6. Rotate the laser 180º, measure the distance between the new project-
ed cross dot and point "C".
7. If the distance is greater than a 3mm (0.125"), the horizontal accuracy
of the laser is out of tolerance and the laser needs to be calibrated.
When the horizontal accuracy is out of
tolerance, remove the screw of the
self-calibration port. Use a 3mm hex
wrench to adjust the weight inside the
laser to make the distance 3mm
Note: If you could not calibrate the accuracy through the self-cali-
bration port, please send the instrument to Johnson Level for service.
12
Self-
Calibration
Port
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