Self-check and calibration, Wall 1 wall 2 fig 1 fig 2 – Johnson Level & Tool Mfg. 40-6640 User Manual

Page 11

8. Self-Check and Calibration

IMPORTANT: It is the responsibility of the user to verify the

calibration of the instrument before each use.

1. Set the instrument on a level flat head tripod centered between two walls

(marked 1 & 2) approximately 15 feet apart. (See fig. 1).

2. Point the instrument directly at wall 1. Turn the laser on and mark the

intersection of the beams 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 intersection of the beams 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
intersection of the beams 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 inter-

section of the beams 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.

Wall 1

Wall 2

Fig 1

Fig 2