Installed on an aboveground pier-type foundation, the scale's low profile allows drivers to access the console (inset) from the truck. Dr Drivers know they're too close to the edge if they hear the tires rub against the welded-on guide rails. Photos: Avery Weigh-Tronix Inc.
By Larry Behrens
Where: Polk County, Wis.
Who: Recycling center and highway department
What: 200,000-lb.-capacity, 70x12-ft. BridgeMont and AVS-5 console with Model 1310 controller
Manufacturer: Avery Weigh-Tronix Inc., Fairmont, Minn.
Distributor/maintenance contractor: Weigh-Rite Scale Co. Inc., Somerset, Wis.
Cost: $52,177 split 50/50
When you're selling something based on weight, every ounce counts.
But the most up-to-date technology isn't cheap. So to pay for an unattended weighing system, two operations pooled financial and logistical resources.
Wisconsin's Polk County Recycling Center processes roughly 4,000 tons of material annually. Load weight was based on average weighments secured periodically from an offsite truck scale — at best, a spotty estimation method.
The 956-square-mile county also uses or sells more than 2,500 tons of salt and salt/sand blends annually, and was billing by number of loader buckets. But because buckets weren't always filled to the same capacity, that method was about as accurate as the recycling operation's.
Then the managers of the two operations had an idea. The county's highway department stores snow and ice control material at the recycling center. Why not find a system that would weigh and track the incoming and outgoing materials of each?
“We needed something that could weigh long and wide trucks as well as trucks with plows attached,” says Supervisor of Highway Administration Kathy Bohn. “We also had to track which road segments the materials were used on.”
The solution is comprised of a 5-inch concrete deck supported by a steel substructure and bottom deck plate. This substructure supports the concrete on the traffic area of the scale and assumes all tension-loading when the scale is in use, leaving the concrete to assume only compression load. Made of virgin polypropylene fiber blended with concrete, the deck resists extreme temperature changes.
Upon approaching the scale, the driver enters an ID number via the console's keypad. The software asks the driver to specify his department and displays the following fields accordingly:Recycling center:Truck numberIncoming/outgoing materialAccount/customer.Highway department:Truck numberIncoming/outgoing materialJob numberSegment numberAccount/customer.
After the data is collected, the driver and the corresponding operation receive a printed ticket as a receipt.
As transactions occur, the controller sends the data via radio frequency (RF) to the recycling center's computer 200 yards away. At the end of the day, the software automatically e-mails transactions to the highway department 15 miles away. If the data can't be transmitted because of, say, a signal interruption, the controller stores the data until transmissions can resume.
Trucks can be weighed before materials are loaded at the recycling center to obtain the empty vehicle weight. The controller stores that figure and, when the fully loaded truck returns to the scale, this empty weight serves as the tare — yielding the net weight of the recycled materials immediately upon the truck's second weighing.
“Transactions are produced in a spreadsheet that shows the amount of recyclables produced by each site within the county,” says Recycling Center Supervisor Mike Voltz.
“Having data stored in a spreadsheet does make our process much easier,” Bohn says.
— Larry Behrens (firstname.lastname@example.org) is product manager for Avery Weigh-Tronix Inc., Fairmont, Minn.