Johnson Level & Tool Mfg. 40-6550 - Manual (Page 20)

Wall
20 ©2005 Johnson Level & Tool
8. Accuracy Self-Check
1. Set up the instrument on a table 65 ft. (20m) away from an indoor
wall, with one of the X-axes facing the wall as indicated by the
“X” marked on the top of the unit.
2. Press the power button to turn the unit on. After the unit auto-levels,
press the range scan button (on either the unit or the remote control)
to put the unit in range scan mode.
3. Press the range scan button two more times to emit a bright laser point.
4. Mark the center of this point on the wall and label it as point “A”.
5. Rotate the unit clockwise by 90 degrees and use the second button
to the right of the range scan button to jog the laser point back
toward the wall and the point marked as “A”.
Note: The laser points might not line up exactly on the same
horizontal plane, but they should be on the same vertical plane
(i.e., in a straight vertical line).
6. Mark the center of this second point on the wall and label it as
point “B”.
7. Repeat steps 5 and 6, marking centers of new points “C” and “D”.
8. Now, measure the distance between the highest and lowest points.
This measurement = “h”.
Note: The maximum distance between any two points should not
exceed the stated accuracy of
≤0.157" (4mm).
40-6540_6550 English 6/28/05 9:44 AM Page 20