Topcon MACHINE CONTROL AG System Five, Руководство оператора

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Laser Setup
Topcon AG System Five Operator’s Manual
3-12
Laser Drift
Laser drift is caused as temperature changes affect the
mechanical leveling system of the laser transmitter. Laser
transmitters have a level sensor that acts like a precision
carpenters level, allowing the transmitter to level to very
accurate specifications.
As changes in temperature affect the mechanical leveling
system, the laser will re-level to a new position. Although the
laser “thinks” this new position is correct, it has induced an
error in the grade. Many lasers have a separate level sensor for
each axis, so the error may be different in each axis.
If grade increases on one side of the laser and decreases on the
other side—or the scraper cuts on one end of the project and
fills on the other end—the laser beam has drifted and is at an
incorrect position (Figure 3-10).
Figure 3-10. Laser Drift
To minimize problems associated with drift, Topcon has
developed lasers with leveling systems that eliminate or greatly
reduce laser drift. The RT-5S transmitter with it’s five arc
second accuracy and even less repeatability specification has
temperature compensation that automatically adjusts as the
outside temperature changes. The RL-H2Sa laser has a five arc
second repeatability specification due to the newly developed
liquid compensated leveling system that has no mechanical
parts to affect the level of the laser beam.
C orrect Beam
B
eam W ith L aser Drift