Johnson Level & Tool Mfg. 40-6530 - Manual (Page 15)

8. Self-Check and Calibration
IMPORTANT: It is the responsibility of the user to verify the
calibration of the instrument before each use.
X-Direction Accuracy Self-Check
1. For clarity, we define the direction of handle as X-direction,
and another direction as Y-direction
2. Place the unit on a platform that is 50’ away from a wall
indoors, with the handle facing the wall head-on. Unlock the
unit and set to low speed.
3. Mark on the wall where the beam hits the wall and mark that as A.
(Note: This test should be done indoors with dim lighting. It’s
critical that the laser mark is easily seen.)
4. Turn the instrument by 180 degrees, mark the beam as point B.
5. Measure the vertical distance between point A and point B. If A &
B are more than 1/16” apart at 50’, the unit is out of calibration.
A
B
50’
50’
©2007 Johnson Level & Tool 15