Figure 12-8.—Grading machine controlled by laser level and laser detector.
and tunneling, the operator of the machine can stay
on the proper alignment and grade. Figure 12-8
shows a laser level mounted on a tripod and a power
grader with laser detectors mounted on each end of
the blade.
5. The laser level shuts off when the laser beam
deflects from horizontal.
6. It increases the number of rod readings, as
each rodman can set elevations without waiting for
the instrumentman, thereby increasing the area of
survey within a given time frame.
QUESTIONS
Q1. What two general types of electronic distance
meters are in common use?
Q2. Assume that you have used an EDM to measure
the slope distance from points A to B and that you
observed the vertical angle using a separate
theodolite. The slope distance is 730.65 meters
and the observed vertical angle is 3°25´30´´. The
recorded heights above the ground for the EDM,
reflector, theodolite, and target are 1.75 meters,
meters, 1.60 meters, and 1.70 meters, respectively.
Calculate the horizontal distance.
Q3. You are using a specially designed short-range
EDM mounted on an optical-reading repeating
theodolite to locate the position of a point. To
what class of positioning systems does your
instrument belong?
Q4. For normal leveling operations, in what mode
should the laser detector on your laser rod be set?
12-8
