A Weighty Proposition

June 1, 2010
Scale systems can help companies optimize billing and productivity in warehouse and DC environments.

Properly managing inventory and billing in warehouse and distribution center (DC) environments often depends upon documenting and weighing freight upon arrival and before shipping. Material handling charges are frequently determined by the weight of the transported load; thus, high-accuracy weighing processes are required to optimize revenue in these applications. Precise weighing can also help ensure customers are invoiced for the exact amount of materials purchased or shipped, maintaining a satisfied customer base and improving inventory management. By enhancing productivity and billing accuracy, a reliable, user-friendly scale system can save companies a significant amount of money every year.

To ensure the weighing process helps rather than hinders operations, the scale system selected should provide efficient results and legal-for-trade accuracy as well as facilitate simple documentation and billing. The most common solutions used in these applications—floor scales, lift truck scales and truck scales—offer unique advantages and should be selected based upon the type, value and amount of commodities handled.

Floor Scales

With a 1-pound graduation, floor scales weigh commodities of moderate value per pound with high accuracy, yielding less potential for revenue loss. They are particularly suited for heavy or bulky boxes and cartons weighing tens to hundreds of pounds with +/- 0.5-pound accuracy.

Floor scales consist of a low-profile, aboveground or pit-mounted rectangular platform featuring integrated electronic weight sensors with no flexures, hydraulics or springs prone to wear. This scale system can be placed at a central location within a warehouse or DC, and it is used in two ways: Personnel can wheel lighter loads onto the scale for weighing, or, for heavier loads, operators can drive lift trucks carrying bundled or palletized commodities directly onto the scale.

For simple lift truck access and to accommodate varying travel patterns, above-ground floor scales may feature ramps on each of the four sides. The scales are also offered in a wide range of sizes and capacities—from a 30-x30-inch scale suitable for 2,000-pound loads to a 96-x-72-inch scale with a capacity of 20,000 pounds.

A floor scale is paired with a digital scale indicator that collects, stores and communicates weight data. This indicator can serve as a local display for manual operations, where operators document readings by hand, or for applications where only the most basic weight data must be gathered.

More advanced indicators automate the weighing process with barcode scanners, incorporated to obtain product identification data for each bundle or pallet. The indicator then uses wireless communications to transmit freight identification and weight data to management’s primary data collection software system, helping to improve productivity and producing instant, accurate invoices for all materials weighed. These data management capabilities, paired with the scales’ high accuracy and ease of operation, make floor scales a common selection in warehouse and DC areas.

One common concern about integrating a floor scale into these fast-paced environments is that the weighing process can prove inconvenient. After receiving a load upon arrival, rather than taking the pallet to its designated storage location, the lift truck driver must divert his or her course to stop past the floor scale, interrupting operational flow. On particularly busy days, weighing becomes even more timeconsuming, as a single floor scale is often used for dozens of lift truck operators. This process may result in measurable productivity loss when multiple drivers must wait for access to the scale.

Lift Truck Scales

An en-route weighing system can help enhance productivity as well as optimize revenue. A lift truck scale, consisting of multiple metal plates and electronic weight sensors, allows drivers to lift, weigh and move loads while recording pertinent material and weight data. The scale installs by attaching to an existing lift truck carriage, and it can be removed from one lift truck and attached to another within minutes.

Rather than a traditional scale indicator, weight data is recorded by an in-cab instrument and displayed and transmitted wirelessly from the lift truck to a back-office collection system. This allows supervisors to monitor and manage freight arrival and shipments in real time, facilitating more efficient, accurate inventory and billing records.

With a 5-pound graduation, lift truck scales have a greater maximum weight increment than floor scales, making them better suited for materials slightly lower in value. As one scale is required per lift truck, this solution may require a higher upfront investment. However, the time saved by allowing lift truck drivers to take incoming freight directly to storage and outgoing materials immediately to the proper shipping area with no extra steps can result in significant time savings and speedy return on investment. These scales can also reduce lift truck wear by eliminating the travel required to access a static floor scale.

Design features that make lift truck scales easier to apply include rugged, one-piece construction, which reduces the likelihood of failure due to frequent, heavy loads. Scale systems may also incorporate large vision windows to ensure lift truck drivers can observe and monitor fork tips throughout material transport.

In addition, a lift truck scale comprised of electronic weight sensors can be configured to deliver accurate results, even if the pallet load is off-center, the mast is tilted, or the lift truck itself is on an uneven floor. In-cab instruments may offer barcode scanners that allow operators to instantly capture all necessary freight data available and then transmit this information alongside weight data to supervisory computer systems.

Truck Scales

Trucks play a pivotal role in material handling operations by transporting bulky structures, multiple cartons of commodities, or bulk dry or liquid goods. The importance of proper weighing is demonstrated on several levels when truckloads of materials are involved. Along with optimizing revenue and ensuring proper material quantity, trucks must conform to stringent state weight regulations. Proper weighing helps companies avert costly fines as well as avoid premature vehicle wear due to excessive loading.

The truck scale design that best satisfies these requirements consists of several scale platforms—one for each truck axle—incorporated into a single foundation, thus allowing users to collect axle and gross vehicle weight in one step. Truck scales can handle loads weighing up to 270,000 pounds with 20-pound graduation. This maximum weight increment is much higher than that of floor and lift truck scales, but well within the requirements for legal-for-trade accuracy when used with loads weighing tens of thousands of pounds. Also, truck scales require a higher capital investment and consume a large footprint. The platform itself ranges from 10 to 24 feet in length and requires a specific ramp length and grade, depending on state regulations.

The scale corresponds with a digital indicator that displays all axle weights and gross weight at once. For increased efficiency, this indicator may be integrated into a standalone control console that facilitates unattended weighing operations. A truck driver simply stops on the scale and swipes an ID card or manually enters an ID number, along with any additional requested data, into the system via the indicator’s pushbuttons or an integrated keyboard. The truck then exits the scale for loading or unloading and afterwards returns to the scale so that an outgoing weight may be obtained.

As an alternative, the indicator may be programmed to maintain the truck’s empty weight as the tare value so the truck must only be weighed once. The console prints a ticket for the driver, which contains the weight of the delivered freight and other pertinent data, and the indicator communicates all collected information to a central software system.

Recent software innovations have made truck scales even more useful by facilitating efficient documentation and management of key weight, commodity and vehicle data. Truck scale management software can be scaled for use with a single computer and linked to a single scale or interfaced with several scales and a full IT network system. Managers may also use the software to set precise parameters, such as vehicle and trailer tares and expiration, as well as oversee invoice generation and customer payment processing.

Regardless of the application, correct weighing practices, including selecting the proper scale system, can help increase revenue in the long run.

Don Halbert is global product manager with Avery Weigh-Tronix, a supplier of industrial scales and weighing systems.

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