The what, when, and why of rugged handhelds

Would you ever take a handheld computer into a swimming pool, drop it from the top of a climbing wall, run it over with a dirt bike, or use it as a hockey puck? Of course not! Yet some manufacturers of "rugged" handheld computers have produced videos showing their products being manhandled in those and other startling ways.

Those fanciful scenarios might seem extreme—after all, how many warehouse associates go swimming or play ice hockey during their shifts? But the tongue-in-cheek demonstrations make a valid point: Some warehousing and transportation environments are remarkably tough on handheld devices, and it pays to have equipment that can stand up to abuse.

The added durability comes at a price, of course, but in certain applications, rugged equipment might well prove the most cost-effective choice. Here's a look at what qualifies a device as "rugged" and the types of applications where these units make economic sense.

What makes a device rugged?
Rugged handheld computers are designed to work where they'll be exposed to potentially damaging conditions, such as bad weather, shocks and drops, high or low temperatures, and particulates like dust or sand. According to systems integrator Barcoding Inc. and handheld computer manufacturer Psion, five factors determine whether a handheld computer qualifies as a rugged device: the outer shell, the keypad, the display, the internal components, and the accessories.

The outer shell absorbs impact and prevents penetration by contaminants. Each shell carries an Ingress Protection (IP) Code rating that consists of two digits. The first refers 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.

It's important that the components be manufactured from the right materials for the application, says Khalid Kidari, director of product management and marketing for DAP Technologies, which makes rugged devices. Depending on the product and the application, lightweight alloys and metals are best for some parts, while plastic that flexes when the device is dropped, so that the plastic absorbs the energy of the impact, is best for others. Devices that are frequently exposed to moisture or salt air should be free of metal that could rust and corrode.

When should you use rugged devices?
Distribution activities, including transportation, freight yard management, direct store delivery, and field service and repair, are ideal for rugged handhelds, says Intermec's Stubbs. In fact, any application where the devices will routinely be exposed to heat, cold, rain, wind, dust, dirt, salt air, and so forth calls for rugged devices. Standard commercial or light-duty industrial equipment simply won't stand up to those conditions. Batteries will quickly run out, screens won't refresh fast enough, and the inner workings will get clogged up or permanently damaged by contaminants.

But even an ordinary warehouse can be tougher on handhelds than you might think, Kidari warns. "If a warehouse is fairly clean and there's little or no dust, then you don't really need full protection and can get away with light industrial devices," he says. A typical warehouse environment, though, has plenty of dust from cardboard and from unsealed concrete floors, he adds.

There's also the danger of damage from impact. Consider the likelihood of damage from forklift collisions. And if warehouse associates are picking or putting away items at anything other than floor level, then it's inevitable that the handheld devices they use will be dropped from on high.

The degree of risk is also an important consideration, says D'Ambrosio of Glacier Computer. Fixed-mount devices that are attached to a forklift or other vehicle are exposed to tough but predictable conditions. But mobile devices, he notes, may encounter a variety of potentially damaging environments, and they must be able to withstand all of them.

Physical conditions are not the only factor to consider. "It's really the business environment that dictates the degree of ruggedness required," observes Psion's Wills. Buyers should ask themselves how dependent their business is on the device's reliable, consistent operation. "The more mission-critical the device is, the more rugged it needs to be," he says. "What would happen to your business if it were not usable?"

Why they make economic sense
Rugged handhelds cost considerably more than standard commercial equipment—often twice as much, depending on the model and the customer's requirements. In addition to design and materials costs, the amount of testing and certifications required raise manufacturers' costs, D'Ambrosio says.

But the list price is simply a starting point, and a host of other factors affect the total cost of ownership for a rugged device. For one thing, users will need to buy fewer of them, rugged equipment makers say. "You have to consider that with a non-ruggedized device, the first time you drop it you'll have to replace it, which means you'll have to keep many extra pieces of equipment on hand," says Wills. "With rugged handhelds, you'll just need a few spares."

For another, rugged handhelds can improve productivity. According to the manufacturers, they rarely fail, and if they do break down, their modular design makes most repairs quick and easy. Their extended battery life also ensures reliable performance throughout the length of a shift and beyond.

In the past, the typical lifespan for ruggedized handheld computers ranged from three to six years, but now it's not unusual for them to last much longer. The manufacturers consulted for this article reported handhelds that are still running after six years or more of around-the-clock operation, including some that are still going strong after 15 years. This longevity makes rugged handhelds an attractive capital investment. "With most customers buying equipment outright on a three-year depreciation cycle," says Psion's Wills, "anything beyond that is free money."

The exotic and the everyday
Considering the abuse that rugged handheld devices are able to take, it's not surprising to find them in some unusual applications. Loggers use them with bar-coded tags on trees that are ready to harvest, growers use them to track produce from field to distribution center, and they even see duty in a brewery, where they safely undergo daily washdowns with a hose along with the rest of the brewing equipment.

But it's not necessary to be in some exotic line of business to consider an investment in ruggedized handheld computers. No matter what type of operation you run, if reliability, productivity, and a return on your investment are high priorities, then rugged devices are worth a look.