technologyreview TRACK AND TRACE
to the level of protection against solid objects, and the second refers to protection against liquids. The lowest IP rating would be “ 11”—protected against a solid object greater
than 50mm (about 2 inches) in diameter—a hand, for
instance—and against falling drops of water, with limited
ingress of water allowed. The highest rating would be
“68”—no dust penetration and protected against long periods of immersion in water under pressure. The highest-rated handheld computers for warehouse and transportation applications on the market today are rated IP 67—
dust-tight and able to withstand immersion in water at
depths of up to one meter (about 3. 3 feet).
Keypads must be designed for use in all sorts of conditions. For example, the buttons have to be big enough that
someone wearing gloves—think of people who work outdoors in winter or in refrigerated warehouses—can accurately enter data, says Mike Wills, vice president, North
American sales, for Psion.
Because rugged handhelds have a long lifespan, keypads
must remain readable for many years. Some common ways
manufacturers increase wear resistance and prevent fading
include molding graphics on the underside of the keys, using
colored plastics instead of painted markings, and applying a
protective coating over painted symbols. Another method is
to use lasers to etch images from top to bottom of the keypad,
so that numbers and letters clearly show through even after
years of use, says Bruce Stubbs, director of industry marketing for Intermec, which makes rugged devices.
Data displays must be easy to read in all conditions.
Touchscreens, made of polycarbonate plastic or specially
strengthened glass, are often used to display information.
Plastic is a good choice for devices that are exposed to severe
drops and impacts to the touchscreen, or used in applications (such as handling some foods and pharmaceuticals)
where glass is prohibited in the vicinity of the product. Glass
is best for devices with graphically based software that relies
heavily on the touchscreen, say Barcoding Inc. and Psion.
Recent advances in strengthened glass production have
made this material more suitable for rugged devices.
Internal components are specially strengthened and are
surrounded by buffering space to prevent damage when a
device is dropped or knocked around. The batteries not
only hold a charge longer, but they also have a longer lifespan—up to two years, rather than the typical six months
for non-rugged devices, according to Stubbs.
And finally, accessories such as docking stations, mounting
hardware, and add-on grips should meet the same standards
for ruggedness and reliability as the mobile device itself.
Some devices are “ruggedized” at the time of final configuration with protective reinforcements that add weight and
bulk to the product, says Ron D’Ambrosio, president and
CEO of rugged device manufacturer Glacier Computer. A
better choice, he says, is one that’s designed for ruggedness
“from the inside out.” For example, using a thicker substrate
in the circuit board provides more stability and less flexing
and vibration while the computer is in use.
What about tablets and iPhones?
There’s been a lot of hype recently about the use of consumer devices like smartphones and tablet computers in
warehousing and distribution applications. Those devices
have their supporters—mostly for their convenience and
low initial cost—but many observers dismiss them as
being too fragile to handle the vibration, falls, and other
impacts that are part and parcel of warehouse operations.
However, ruggedized tablets are now making inroads
in the mobile device market. Some users like them
because they find the bigger screen easier to read, especially for reading large quantities of data or graphics like
maps and technical drawings.
Versatility is another attraction. Because the tablets’
functionality resides in the software, users gain flexibility,
says Khalid Kidari, director of product management and
marketing for DAP Technologies, which includes both
rugged tablets and handhelds in its product lineup. One
example is differing keyboard views. “Sometimes you
might want to display numbers or just alpha keys. That’s
flexibility you do not get with a physical keyboard.” Other
advantages cited by vendors include the ability to access
multiple software and communications technologies in a
single device, and the productivity gained by using one
device to carry out a variety of functions.
