When the feed sensor costs between $1,500 and $2,000 to replace and you have one on each side of the screed, you want them to last throughout the paving season. Here’s how to increase the chances of protecting the feed sensor from contamination, and protecting the quality of your mat at the same time.
The typical feed sensor sends a beam to the top of the head of material at a rate of 10 times per second, reading the material’s height. It sends a signal to the controls system to help you monitor and maintain the correct height, also assisting in the correct speed of mix entering the augers. The sensor is your constant eyeball on the mix to help you maintain quality. If you close that eye with a patch of asphalt and goop, yet still try to use faulty readings, you’re paving blindly.
To keep the feed sensor clean, wipe it with a rag doused with some brake cleaner at the end of every paving shift. Do this while the equipment is hot to help get any stray material to wipe away easily. Do this as part of the daily equipment shutdown routine.
Also at the end of the day, take a look at the feed sensor wires. Inspect these to make sure they aren’t being stretched and cut. Make sure they aren’t pinched between the tow arm and the frame of the tractor at the end of the day.
Another way to keep the feed sensor clean is to use best paving practices.
When the paving crew begins the first pull of the shift, it’s typical to fill up the augers and overfeed the extensions. Train the team to be careful with this excess of material. Don’t overfeed so much that the head of material rises too high and touches or clogs the feed sensor. Definitely don’t let the mix rise above and bury the feed sensor.
Also pay close attention to the endgate when paving alongside driveways. Crews have a tendency to pile up mix—because they don’t want to run out—and overfeed the head of material in preparation for sliding out to accommodate the driveway. You definitely want more material here so you don’t starve the area or create too much handwork for the crew, but you must keep an eye on quality.
As you slide the extension back in at the end of the driveway, watch out for the head of material because it will rise again. This is another chance for it to get too high and come up to contact the feed sensor.
By keeping your eye on the feed sensor, you give this tool its best chance to keep an eye on your material. Let the sensor do its job to help you pave a top quality mat by keeping it clean and clear of the mix and muck that could lead to its expensive replacement.
John Ball is the proprietor of Top Quality Paving & Training, Manchester, New Hampshire. He provides personal, on-site paving consulting services around the United States and into Canada. For more information, contact him at (603) 493-1458 or firstname.lastname@example.org.