Johnson Level & Tool Mfg. 40-6510 - Manual (Page 19)

©2007 Johnson Level & Tool 19
2. Put the instrument in the vertical position on the tripod.
3. Face the instrument
towards wall A, and adjust
the leveling knob to center
the bubble of Z-direction
vial. Project laser beam
and mark e2 for the laser
point shown on wall A.
4. Measure the distance between e1 and e2.
5. Turn the instrument 180° to face wall B, and turn the adjusting
knob and mark the laser point projected on wall B f2.
6. The distance between e1 and e2 should equal the distance
between f1 and f2.
Instrument Accuracy Self-check
1. Put the instrument on a
tripod in the center of two
parallel walls that are 50 ft.
apart, with the instrument
facing left, as shown. Aim the
instrument at wall A and wall
B respectively to project the
laser beams, and mark point a1 and point b1 for the laser
points shown on walls.
2. Move the instrument 3 ft. (1m) from wall A and level it, with
the front still facing left. Repeat step 1, and mark the project-
ed red laser points as a2 and b2;