Weighty Issues

Features - General Business

By following a few best practices, recyclers can ensure their scales offer optimal performance.

July 8, 2013
Recycling Today Staff

In the recycling and solid waste industry, uptime is of utmost importance. Most facilities experience long lines at the scale, and so they place a premium on getting trucks in and out quickly. But, have you ever stopped to think about how much you could be losing per truck?

When you placed your scale in service, the state agency responsible for certifying weights and measures ensured that it met the necessary regulatory requirements, and the manufacturer assured you that the scale was capable of holding to accurate tolerances. However, external variables and real-world issues can knock your scale out of calibration and cost you a lot of money, as the chart to the right illustrates.

A simple error of one increment (20 pounds) can lead to $30,000 in annual product loss! This is a real example and is based on a product with a value of 5 cents per pound and a duty cycle of 100 weighments per day.

For this reason, consider implementing the following best practices.


1. Implement A Calibration & Inspection Agreement.
The simplest step you can take is to implement a calibration and inspection agreement with your service provider. Depending on the requirements and type of weighing device and the frequency required to assure accurate weighing and to reduce the risk of loss because of an inaccurate scale, inspection costs can be as low as $500 annually. Compared with the potential loss figures, this is a worthwhile investment.

How often should your scale be inspected? Kansas City, Mo.-based Fairbanks Scales, an industrial weighing equipment and service provider, recommends a minimum of two inspections per year for most scales, but the sort of heavy traffic that recycling and solid waste facilities experience can easily justify more frequent verification, inspection and service. Consult with your scale service company about a schedule that works best for your company.

What should you look for in a service provider? “Investigate the longevity of the company,” recommends Mike Wilkinson, product manager at Fairbanks. “How long have they been in business? Do they know the industry? Do they have solutions for the challenges that your business faces? Another good check point is to compare the services provided among service providers,” he suggests.

The No. 1 priority of Fairbanks’ calibration and inspection program is to ensure the scale is accurate by testing with certified weights that are traceable to a federal standard, Wilkinson says. As a value-added component of the inspection, Fairbanks reviews and inspects the electronic and mechanical components to ensure there is no wear or issues looming that could result in inaccuracies or unexpected downtime.

Regardless of the company servicing your scale, it should be able to document the test weights’ traceability.

After inspection, be sure the service company provides a written evaluation of the inspection and reviews the condition with you. This is by far the simplest and most economical way to avoid inaccuracies and unexpected downtime.

2. Keep the Scale Foundation Clean.
Recycling and solid waste operations can generate a lot of debris. Be sure to regularly remove the buildup to avoid scale inaccuracies. A pressure sprayer is a fast and easy way to clear debris and keep the scale and foundation free of buildup. Be sure that your junction boxes, electronics and load cells are properly rated to withstand pressure washing; otherwise, you may cause damage.

3. Perform Your Own Inspection.
Inspect for anomalies. A properly operating scale is dependent on every component working together. Inspect the weighbridge for damage or signs of wear and corrosion. During your inspection:

  • Examine the junction boxes inside and out. Do they show signs of damage, corrosion or moisture entry?
  • Module connection hardware should be intact and not damaged.
  • Check the load cells for damage, corrosion and signs of moisture entry into the enclosure and the cable entry gland. Liquid is a good conductor and can easily short your electronics if allowed to enter the sensing element area.
  • Inspect quick-disconnect load cell cables frequently as they are responsible for many avoidable failures.
  • Inspect the wiring for damage. Exposed conductors cause communication errors when wet and are usually the culprit of erratic performance.
  • Your scale’s paint system isn’t just for good looks; it’s a critical barrier against scale corrosion on your weighbridge steel. Repaint if you expect maximum life from the weighbridge steel.
  • If your scale has cover plates, inspect the connection hardware and make sure they are there, functional and free from mud and debris.
  • Grease the load cell cups at recommended intervals. Some manufacturers incorporate zerk type fittings, allowing grease application without physically separating the load cell components.
  • Inspect concrete for signs of failure. Address these issues as soon as possible.

4. Make Adjustments.
Your weigh-bridge will expand and contract slightly at different times of the year. This thermal expansion requires attention and readjustment of your checking. The checking system on your scale keeps the weighbridge in place as it naturally rocks and moves from traffic. Insufficient gap in the checking can cause binding and weighing errors. Too much gap in the checking allows excessive movement, including a scale tipping. Excessive movement adds unnecessary wear to components.

5. Keep Your Scale Grounded.
Today’s truck scales use sophisticated electronics to communicate weighment data to the instrument. A securely grounded scale is a basic defense from lightning and power surges. Be sure that the scale is connected to the manufacturer’s specified grounding system and that there are no interruptions in this system. Transient voltage seeks the easiest path to ground. If your scale isn’t grounded through a ground rod connection, it surely is grounded through other components.

6. Monitor Your Scale's Use.
You probably don’t have the time to monitor how fast traffic enters and exits the scale. However, keep in mind that while the scale is designed to slightly move with traffic, abusive and aggressive entrance and exiting of traffic accelerates wear. Again, taxing the scale means more wear and more dollars spent in repairs. Many scale manufacturers offer accessories to promote traffic discipline while entering and exiting your scale. Traffic signals and guide post kits at the approach and exit can manage traffic flow and truck speed effectively for a small investment.


7. Install Accessories Where Necessary.
Consider the accessories below to prevent issues with your scale.

  • Riser plates – “Be very wary of a low-profile scales,” Wilkinson says. “Reducing the clearance under the scale gets you two things: One, it takes less debris accumulation to impact the accuracy of a low-profile scale. Secondly, it makes cleaning your scale much more difficult, as the underside is impossible to reach.” Riser plates elevate the weighbridge, reducing the risk of debris accumulation and providing clearance for cleaning and inspection.
  • Load cell boots – Exposed to debris, weather, moisture and debris that has migrated below the deck, your load cells operate in the worst environment possible. Load cell boots act like a protective glove and prevent debris from affecting load cell operation.
  • Steel and rubber belting – At each end of your scale is a small gap between the scale and foundation. Installing T-belting along this gap between the scale and foundation wall helps to prevent accumulation of dirt and debris.

Go Digital
To keep your inspections frequent without losing too much business to downtime, consider switching to a digital scale. “Let’s say a typical scale has eight to 10 load cells,” Wilkinson says. “If it’s an analog setup, it could take four to six hours—the bulk of a day—to get your scale calibrated correctly. Whereas, with a digital system, we can see the performance of each individual load cell on the instrument screen. With that ease of access, you’re talking minutes to half an hour for recalibration.” In the end, how you implement these best practices is up to you. One thing is certain: Neglecting your scale costs profit.

Double Down
A multimaterial sorting center ensures accuracy throughout its operating with its weighing system.

Boomerang Environment, located in Laval, Quebec, is a multimaterial sorting center that specializes in sorting small-, medium- and large-sized plastics. Equipped with state-of-the-art optical sorting technology, Boomerang Environment makes it possible to recycle all groups and subgroups of plastic materials. The facility accepts postindustrial and postconsumer plastic. Once sorted, the plastic is baled by category and sold.

Because the material is purchased directly by Boomerang, it is critical that incoming as well as outbound vehicles transporting the plastics are accurately weighed to ensure the exact quantities are being transported.

Because each type of plastic has its own price, customers purchase truckloads of a single category of plastic. Therefore, it is important to document the exact weight of the vehicle to optimize billing accuracy and to maintain customer satisfaction.

“Accuracy is key in our business,” says Alina Manji, sales and marketing director at Boomerang Environment. “If the weight of a certain material is off even a little bit, it can affect our billing documentation and our credibility with our customers.”

In addition to optimizing weight data accuracy, Boomerang also dealt with the challenge of heavy traffic because only one scale was used to weigh incoming and outbound vehicles. This not only resulted in production downtime with drivers waiting around for their turns, but it also presented safety issues for facility employees and occupants.

To resolve these issues and ensure efficient weighing procedures, Boomerang implemented two concrete BridgeMont XL truck scales from Avery Weigh-Tronix with PC connectivity and printers. These extra-long, 75-foot scales provide a rugged weighing solution that can easily handle heavy traffic and axle loads beyond legal highway limits, according to Avery Weigh-Tronix.

One of the truck scales is located outside of the facility and is used to weigh the incoming vehicles loaded with mixed materials. This setup allows drivers to have visible access to their vehicles’ weights before entering the facility.

The second scale is located inside the facility and weighs the sorted materials, as empty trucks are placed on the scale and loaded to capacity. To facilitate simple and accurate documentation, track sorted materials and customer billing, both scales are directly linked to the facility’s PC software system located in the administrative office—allowing the weight to be recorded directly to the computer and sent to the printer for documentation.

“The truck scales from Avery Weigh-Tronix allow everything to be done from the administrative desk, eliminating the risk of accidents in the facility,” adds Manji. “Plus, drivers don’t have to remember to manually record their data each time.”

By using two truck scales, Boomerang experienced fast in/out times for all vehicles, eliminating long lines to the weigh station and operation downtime. This also allows operators to maximize the number of loads weighed in a given amount of time, ultimately optimizing overall profits, while, in turn, providing an ecofriendly weighing process. Additionally, the scales’ capability of directly connecting to custom software allows for fast and accurate data collection. Before scales offered this feature, companies would have to print out each transaction and then re-enter it into their program manually—increasing the potential for human error. This may lead to inaccurate invoices or customer dissatisfaction. Continuous, up-to-date documentation also permits all personnel to view data on or off the site.

“Avery Weigh-Tronix truck scales provide reliable measurements, fast results and user-friendly operation,” Manji says. “Plus, the fact that they come with exceptional customer service make them a clear-cut weighing solution for us.”

Upon implementation of the truck scales, Boomerang has eliminated the constant back and forth from the administration desk to the scale booth—streamlining the process to save time and prevent safety risks. With continuous, up-to-date weight information for each vehicle, Boomerang can place the necessary records directly in the customer’s file, ensuring reliable weight data every time.

This article was submitted on behalf of Avery Weigh-Tronix. To learn more about Avery Weigh-Tronix equipment and solutions, visit www.wtxweb.com.

For more information about Boomerang Environment, visit http://www.boomerangenv.com.

This article was contributed on behalf of Kansas City, Mo.-based Fairbanks Scales. More information on the company is available at