9 Calibration
76 DG711 and DG511 Pipe Laser User Guide
Checking the calibration of your
pipe laser is easy. All you need is
an engineer’s rule and your pipe
laser:
1Select a level road, parking lot
or field whose rise is not more than
10 cm in 30 m (4 inches in 100 ft).
2Choose two points (A and B)
about 30 m (100 ft) apart. The
distance does not have to be
measured, but the points must be
found, so mark them well.
3Set up the pipe laser just behind
the lowest point and rough level.
4Turn on the pipe laser and let it
warm up for about 10 minutes.
5Set the grade counter to
0.000%.
6Aim the laser beam so that it
passes over points A and B. Allow
the pipe laser to self-level.
7Accurately measure the
elevation to the center of the beam
at point A and record the elevation
as A1 in a table like the one shown
below:
8Accurately measure the
elevation to the center of the beam
at point B and record the elevation
as B1.
9Move the pipe laser behind
point B and aim the laser beam so
that it passes over points A and B.
Allow the pipe laser to self-level.
10 Accurately measure the
elevation to the center of the beam
at point B and record the elevation
as B2.
11 Accurately measure the
elevation to the center of the beam
at point A and record the elevation
as A2.
Point A Point B
Second Reading A2 B2
First Reading A1 B1
Difference A2 - A1 B2 - B1
Error in 30 m
(100 ft)
(A2 - A1) – (B2 - B1)
2