Product Manual

18 • LMPL20
Setting Excavation, Base Material and Pipe Elevation (Fig. 29)
1. To accurately set the base elevation for pipe laser use, you must be able to calculate the base elevation
from the center of the pipe laser beam.
Using the sample information below, you will be able to calculate your base elevation as described above.
• Consider a pipe diameter of 12" (300mm)
• Use a pipe thickness of 1" (25mm)
• Consider a base material thickness of 6" (150mm)
Example:
To calculate the base elevation, take the pipe radius 12" divided by 2 = 6" (300mm/2 = 150mm)
Next using the pipe thickness and the base material (1" or 25mm) and (6" or 150mm) respectively
Calculate the distance from beam to base elevation as follows
Pipe Radius + Pipe Thickness + Base Material Thickness = Base Elevation
6" + 1" + 6" = 13" or 150mm + 25mm + 150mm = 325mm
2. You may now utilize any leveling rod, direct elevation rod or grade stick and the pipe laser beam to
control the excavation depth by marking a reference point on your rod at the height detailed above, (13"
or 325mm). Utilize the beam control of the LM-PL20 to match up to the marks on the grade stick or
level rod.
3. In some cases, it may be necessary to set a sub base elevation to begin work. To set a sub-base
elevation, calculate the distance from the center of the beam as follows:
Example:
To calculate the sub-base, utilize the information below.
Pipe Diameter: 12" (300mm) as detailed in the example above
Pipe thickness: 1" (25mm) as detailed in the example above
Distance from beam to sub base elevation
To calculate the first step, take the pipe radius 12" divided by 2 = 6" (300mm/2 = 150mm)
Next using the pipe thickness and the base material (1" or 25mm) and (6" or 150mm) respectively
Calculate the sub-base elevation as follows
Pipe Radius + Pipe Thickness = Sub-Base Elevation
6" + 1" = 7" or 150mm + 25mm = 175mm
4. You may now utilize any leveling rod, direct elevation rod or grade stick and the pipe laser beam to
control the elevation of the sub-base material by marking a reference point on your rod at the
height detailed above, (7" or 175mm).
5. Finally to set the LMPL20 to the correct elevation for use, place the pipe target in the pipe using the
target associated with the size of pipe you are setting. Then adjust the pipe until the laser beam is
precisely in the center of the alignment center of the target. Ensure that the center of the beam is
exactly in the center of the bulls-eye on the target. Once there, set the pipe and fill accordingly to
maintain grade.
In-the-Pipe Set up. (Fig. 30)
Assuming that some pipe has already been installed or laid, the LM-PL20 Pipe Laser can easily be positioned
inside the pipe for additional use.