| |
| Illustration 1 | g06008436 |
|
Left Side of Screed (1) Material height sonic sensor | |
Material height sonic sensor (1) is mounted on the left side of the screed. The right material height sonic sensor (not shown) is located in the same relative position on the right side of the screed. Sonic sensors can be used in place of the material height paddles.
Material height sonic sensors emit sound waves. The machine electronic control system monitors the time required for the sound waves to reflect off the paving material and return to the sensor. The elapsed time indicates the amount of paving material present.
The right and left material height sensors provide a pulse-width modulated signals to the machine ECM.
Each material height sensor has a red indicator light on the end of the sensor. This indicator light is illuminated when the sensor is working properly. This indicator light blinks when the sensor has failed or the sensor is operating outside the working range.
| |
| Illustration 2 | g06008440 |
|
Rear of Machine (2) Protective housing (3) Material height paddle (conveyor) (4) Protective housing (5) Material height paddle (auger) | |
The material height paddle sensor for the conveyor (left shown) is enclosed inside protective housing (2) and is connected to material height paddle (3). The material height paddle sensor for the auger (left shown) is enclosed inside protective housing (4). The sensor is connected by a rod to material height paddle (5).
Note: The material height paddle sensors for the right conveyor and right auger are identical. These sensors are located in the same relative position on the right side of the machine.
During paving operation, the material height paddle for the conveyor rests on the paving material at the rear end of the conveyor. The greater the amount of paving material at the end of the conveyor, the farther the paddle is pushed toward the rear of the machine. The material height paddle for the auger rests on the asphalt at the outboard side of the auger. The greater the amount of asphalt at the end of the auger, the farther the paddle is pushed toward the outside of the machine. The paddle sensors convert the position of the paddle to an electrical signal.