9 Calibration
78 DG711 and DG511 Pipe Laser User Guide
Grade Check 9.3
After the first 8–15 m (25–50 ft) of
pipe has been laid, it is
recommended that you make a
grade check to ensure that the setup
is correct, and that the system is
properly operating.
The illustration shows a method for
checking grade.
1Using a transit level, or an
automatic level and a grade rod,
take a reading at the beginning of
the pipe “A”.
2Using the same instruments,
obtain a level reading at the end of
the pipe “B”.
3The difference between the
readings equals the rise over the
run.
4In terms of % of grade, rise
divided by the run times 100 equals
the percent of grade.
Note – The user of this equipment
is expected to follow all operating
instructions and make periodic
checks on the proper grade,
elevation, and line of the pipe as it
is being laid. Trimble or its
representatives assumes no
responsibility for improperly laid
pipe.
A B