A task group of ASTM Committee F08 on Sports Equipment and Facilities had fun when they gathered to devise a volume test for backpacks. They wanted to use a standard fill specimen that would be easy to find as well as effective, and considered dog food, dominoes, buttons, Ping-Pong balls, dried beans, chopped plastic tubes, plastic washers, foam-packing peanuts, golf and tennis balls. Eventually they chose 20-mm plastic balls as a fill specimen for F 2153, Standard Test Method for Measurement of Backpack Capacity. The new standard uses balls, a piston, and cylinder to measure backpack volumes.

Steve Nagode, a Quality Assurance Lab testing manager for Recreational Equipment Inc., Sumner, Wash., says the method will provide testers with an accurate measure of capacity as well as an element of fun, because “it’s also fun to have 50,000 little balls rolling around the lab.”

The 20 mm balls will be easily accessible for testing. “After developing some guidelines such as not edible, not compressible, density of about 10 lbs. per 1000 cubic in., easy to purchase, and pieces that were relatively slippery to one another,” says Nagode, “the 20-mm plastic spheres were the obvious choice. The spheres are sold as floats to reduce evaporation and hold heat in liquid baths for industry.”

There are as many test methods as manufacturers, Nagode says, and the standard will provide a consistent measure of backpack size that is suitable for manufacturers and consumers requirements. “Since we meet at our trade shows we have excellent cooperation among manufacturers, and I suspect 95 percent of backpack manufacturers are now using this standard,” he says.

F 2153 measures backpacks and related bags with capacities greater than 4 L, such as lumbar packs, soft rucksacks, internal and external frame packs, duffel bags, and travel packs. It covers areas completely enclosed by fabric that are not mesh pockets, water bottle holders, or compressor pockets.

Nagode chaired the task group of consumers, retailers, manufacturers, and consumer-magazine editors. The standard they developed will help manufacturers to compare measurement capacity and communicate it to consumers. “It is then up to the manufacturers to list the capacities in their catalogs, hang tags and sales literature, and reference the ASTM standard,” Nagode says. “It also helps when the consumer magazines pick up on these standards and adopt them for their articles and gear reviews.”

Direct technical comments to Steve Nagode, Recreational Equipment Inc., Distribution Center-QA Lab, Sumner, W. Va. (phone: 253/891-2577). Committee F08 meets Nov. 6-9 in Miami Beach. For membership or meeting details, contact Jim Olshefsky, director of ASTM Committee Services (phone: 610/832-9714). //

Copyright 2002, ASTM