Chapter 6  Building Layout
165
holder, Figure 6-25, or it can be attached to an
excavator or backhoe, Figure 6-26. Operators of
excavating equipment can work the entire job
site without stopping to check grade levels. The
laser level continuously monitors grade, elimi-
nating excess excavation.
The operator places the bucket or blade
cutting edge on the benchmark or finished
elevation. Then, the receiver is adjusted up or
down on the machine and the operator tightens
the clamp when the “on-grade” point is reached.
The receiver “catches” the laser beam from the
rotating transmitter and signals the operator
whether measured surface is above, below, or
on grade.
The laser level is also adapted to other
construction tasks to establish either level or
plumb lines. Horizontal operations for which
it might be used include leveling suspended
ceiling grids and leveling raised-access
computer floors. Vertical operations include
plumbing partitions, curtain walls, posts,
columns, elevator shafts, or any operation
requiring a vertical reference point.
Figure 6-25. A rod holder moves the receiver up or
down until it is on line of sight with the laser level.
(Spectra-Physics Laserplane, Inc.)
Figure 6-26. A laser receiver can be attached to an
excavating machine, speeding up the excavation
process. (Spectra-Physics Laserplane, Inc.)