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5. Measure the distance 'e' from Dot 'M' to the laser line, as per
the Figure.
6. If 'e' > 1.5mm, the instrument is out of tolerance and must be
calibrated.
Horizontal Pitch Accuracy Check
Pitch accuracy refers to the accuracy of the laser between the tool
and the wall, and ensures that the horizontal beam is level between
the tool and the wall.
1. Set up two survey-staffs, OR use two walls, both a minimum
of 15 ft (5m) from each other.
2. Set the instrument on a level tripod as close as possible to
wall A.
3. Power on all laser lines, and move the laser until the cross dot
projects on staff/wall A. Make a mark and label as 'A1'.
4. Rotate the instrument 180° and make the cross dot project on
staff/wall B. Make a mark and label as 'B1'.
©2016 Johnson Level & Tool - Rev. 1
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