Rugged computers are more than just “hard shells”
Even professional users of rugged tablets and rugged handhelds are sometimes unsure of what defines a “rugged computer,” which tests validate ruggedness and how these tests are carried out. Let us tell you about IP ratings, MIL-STD-810G and other rugged specifications. Understanding rugged specs is the key to choosing the right rugged mobile computer for your situation.
Rugged vs. “ruggedized” computers
A truly rugged computer is much more than just a normal computer wrapped in a tough outer case. Consider the difference between a “rugged” computer and a “ruggedized” computer (or tablet or smartphone). The term “ruggedized” gives the sense that fragile internal components have been somehow protected — but a truly rugged computer is designed from the inside out to operate reliably in very harsh environments and conditions.
Tough and durable mobile computers and smartphones are gaining in demand and popularity. Some mainstream devices are advertised as rugged because of features such as water resistance, but these devices are ruggedized, not truly rugged. They might be waterproof, but they lack other aspects of ruggedness, such as the ability to withstand vibrations or shocks and to function well in extreme temperatures.
How do we test our rugged handhelds?
To be considered rugged, computers have to undergo multiple tests for ruggedness. The industry standards are MIL-STD test methods and the Ingress Protection scale.
- MIL-STD tests, i.e. the United States military standard for equipment, include twenty-four laboratory test methods that ensure equipment can handle low pressure at high altitudes; exposure to high and low temperatures, plus temperature shocks; rain; humidity; sand and dust exposure; leakage; and shock and vibration.
- The Ingress Protection scale measures devices for protection against dust and liquids. The ratings are displayed as a two-digit number. The first digit reflects the level of protection against dust, and the second digit reflects the level of protection against liquids (water). An IP65 rating would ensure complete protection against dust and protection against water jets.
These testing standards measure a computer’s ability to withstand the toughest environments in the world. Here’s how the most important tests are carried out for individual environmental factors:
Drop and shock testing. Eight different drop test procedures cause shock or impact in different ways. The “transit drop test” is the most cited. It requires items to survive a total of 26 drops from a height of 122 cm, on each face, edge and corner, onto a hard surface such as concrete.
Liquid-resistance testing. During water-resistance tests, a computer is exposed to powerful water jets from many directions. The test duration, water volume and water pressure vary depending on the rating.
Vibration testing. Vibration tests use laboratory shakers to simulate being on a vehicle or being carried by a person, with variations in the vibrations’ wave form, frequency and intensity depending on the type of device and the environment being simulated.
Sand and dust testing. Dust-resistance procedures test ingress of small dust particles. Flour and sand are projected onto the device at variable high wind speeds and high temperatures for several hours as the device is rotated.
Extreme temperature testing. Testing for operability in high and low temperatures includes exposing the device to extreme heat or cold while it is turned off (storage), while it is being turned on and used (operation), and while it is being used in normal operational temperatures after having been exposed to higher storage temperatures (tactical-standby to operational).
Humidity testing. During humidity testing, computers are exposed to tropical heat with humidity well over 90 percent for several days. Many of the same features that make mobile computers liquid-resistant also help prevent damage from high humidity.
Creating a rugged computer
How do manufacturers make rugged mobile devices that can pass these tests and earn high MIL-STD and IP ratings?
Here are a few ways:
- Unlike normal computers, most rugged computers have no moving parts inside, such as fans or rotating hard drives. Instead of rotating hard drives, rugged computers have solid-state drives — drives without moving mechanical components — that are more resistant to physical shock.
- Rugged computers contain stiffeners, often made out of aluminium, to prevent inside components and boards from flexing during an impact. The outer shell (case) and bumpers are designed to absorb the energy from a drop to prevent internal damage.
- The touchscreen on a normal smartphone or computer is basically glass with a coating to make it sensitive to touch. Rugged computers have displays that use chemically strengthened glass to prevent against scratches and cracks. The displays can also be positioned lower than the surrounding cases to decrease their vulnerability.
- A display backlight is used to improve outdoor readability, even in direct sunlight.
- Some rugged computers are fitted with internal heaters in order to operate successfully in very cold environments. The heater warms components to an acceptable operating level and eliminates condensation that arises from temperature shifts.
In short, every single detail and small part of a truly rugged computer is researched, developed and chosen to make the computer as rugged as possible.
With a deeper understanding of the standards and tests for ruggedness, you’ll be better equipped to choose the rugged mobile computer, tablet or smartphone that suits your unique needs.
If you want a rugged computer, don’t buy a ruggedized computer. Rugged computers are built — inside and out — to be rugged. No fragile parts wrapped in a hard shell here.