Johnson Level & Tool Mfg. 40-6530 - Manual (Page 16)

16 ©2007 Johnson Level & Tool
6. Turn the instrument by 90° and place it on the platform, with
the operating panel facing you. Perform Y-direction self-check
with the same method as X-direction self-check, and mark
point C and point D by turns.
7. If point C and point D are within 1/16” at 50’, the accuracy is
within tolerance. Otherwise reference section 12 of this
document.
Accuracy Calibration
1. Screw off the adjustment-hole bolt with the cross screwdriver,
and adjust the fine-adjustment bolt in the instrument core with a
flat head screwdriver until the laser line in within 1/16” at 50’.
2. Check the accuracy of X-direction with the same method as that
of Y-direction. If the accuracy is beyond tolerance, make the
calibration of X-direction through the adjustment hole with the
same method as above.
3. After calibration, rotate the
instrument by 90 degrees in turn to make sure that the lines on
the wall should be within 1/16” at 50’.
4. Reinstall the adjustment-hole bolt.