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©2008 Johnson Level & Tool
12
©2008 Johnson Level & Tool
X-Direction Accuracy Calibration
1. Turn the lock knob to the “OFF’ position.
2. Remove the rubber plug from the X-direction self-calibration
aperture inside the battery compartment. Adjust the weight
screw inside the instrument core
with a flathead screwdriver.
3. If point A is above point O, rotate
the screwdriver counterclock-
wise. If point A is under the point
O, rotate the screwdriver clock-
wise. (Rotating the screwdriver 1
rotation will adjust the laser line 1mm).
4. Check the accuracy again following the X direction accuracy
self-check. If the accuracy is still beyond specification, read-
just the weight screw again until the accuracy is correct.
Y-Direction Accuracy Self-Check
1. Rotate the instrument 90 degrees and place it on the platform.
2. Check the accuracy of Y-direction with the same method as
that of X-direction (mark the point as C and D).
3. If the accuracy is beyond specification the unit can be
calibrated as follows.
X-direction Self-
calibration aperture
1621H-English 9/4/08 9:05 AM Page 12
