Press button for the third time, both the horizontal line and vertical line are on at the same time.
Press button for the forth time, both the horizontal line and vertical line are off, there is no laser output.
5. Self-check and calibration
5.1 Horizontal line accuracy self-check (transversely)
a) Find a smooth wall, set up the instrument on the tripod which is 5 meters away from the wall.
b) Face the instrument on the wall, unlock it and power on all laser lines, there will be a cross laser
line on the wall, set the center of cross line as A dot.
c) Mark A dot and M dot on the horizontal line separately (the distance between both dots is about 2.5m).
d) Rotate the instrument, make B dot 5m away A dot.
e) Measure the distance e from M dot to the laser line
f) If e>1.5mm, the instrument accuracy is out of tolerance, it needs repair.
5.2. Horizontal accuracy self-check (longitudinal)
a) Set up two survey-staffs that are 5 meters away from each other (or two parallel walls that are more than 5m away
from each other).
b) Set the instrument on the elevating or tripod, and
t
hen place the instrument at the center between the two survey-staff,
