Paving Principles and Control Methods
P-32+ and P-32 Operator’s Manual P/ N: 1001547-01
While in Stringline Mode, the grade indicators display left/ right and centered arrows. You can select the mode
through the GC-35 Slope Sensor, using firmware version 1.1 or newer, under the Sonic Tracker 3 menu item.
The GC-35 screen displays an icon as a reminder of which mode is active.
Figure 25: Timed Sound Pulses Determine Distance (ST-3 and Sonic Tracker I I )
For Laser Control a laser transmitter is used to produce a plane of light which becomes the grade control
reference for the job site. The Laser Receiver controls the screed to lay a mat parallel to the laser beam
When the laser beam is in the center of the receiver, it indicates an On-Grade signal (Figure 26).
Figure 26: Laser Control – On-Grade
As the screed is raised, the beam of light hits the Laser Receiver below the center and a lower signal is indicated
(Figure 27 on page 16).
Echo Bounces Off
Physical Grade Reference
Tracker Uses Echo's Ret urn Time To
Calculate Distance To Grade Referen
Sonic Tracker I I shown.
Both the ST-3 and Sonic
Tracker I I use similar