Nailing down 'rugged'

     Just a few years ago, all rugged notebooks were typically subjected to a common set of tests, each designed to determine a product's ability to survive in the real world environments that are common to rugged computing. Now, with a wider variety of products on the market that are tested to a diverse set of rugged specifications, the job of selecting a notebook has become significantly more difficult — yet more important than ever — as buyers must ensure that the level of durability appropriately matches the environmental requirements of the organization.

     Some manufacturers will avoid discussions regarding product ruggedness and instead shift the focus to annual failure rates (AFRs). While annual failure rates are important, they do not accurately reflect a product's ability to survive in a given environment. This is because AFRs use a broad base of deployed units, assume that all environments and usage models are the same, and that every notebook in the field is exposed to the same amount of torture. In addition, this measurement is skewed by the lack of a standard definition of what exactly comprises a failure. Without this and a common usage environment for comparison, AFRs are not an accurate way to predict how a product will perform in your environment. The key is ruggedness. The question then becomes, how rugged of a notebook do law enforcement officers need?

     Department of Defense Standard 810F establishes laboratory test methods that replicate the environmental effects a product will experience throughout its service life and, in turn, provides IT professionals a fairly straightforward way to predict how a product will perform in real world situations. The key is to determine which individual tests within the MIL-STD replicate the specific environment your notebooks will experience. Balancing the approach between ruggedness and price will ensure the notebook you purchase is tough enough for your environment and has the lowest total cost of ownership.

     The following categories of MIL-STD tests provide a guideline to help assess which level of ruggedness is best for your particular environment.

Vibration

     Vibration is easily the most important rugged feature for vehicle deployed workforces. Not only does a notebook need to survive up to five years of constant vibration and jarring without coming apart at the seams, it has to be able to function while flying down the roughest of roads at high speeds. There are several vibration tests that simulate these conditions:

  • MIL-STD 810F, Method 514.5, Procedure I, Category 24, Fig 514.5C-17 is a non-operating "general integrity" test that exposes the unit to multiple vibration frequencies to ensure the notebook remains in tact and operational over time.
  • MIL-STD 810F, Method 514.5, Procedure I, Category 24, Fig 514.5C-18 is a non-operational test that simulates helicopter transport and exposes the unit to individual vibration frequencies to determine if any one frequency can cause structural damage over time.
  • MIL-STD-810F Method 514.5 Procedure I, Category 20, Fig 514.5C-1 is an operational test that simulates 1,000 miles of transportation and ensures the notebook can function even over rough roads.
  • ASTM 4169-99 Truck Assurance Level II Schedule E 11.5.2 is an alternative operating test that simulates truck transport.

     During operational tests, i.e. MIL-STD-810F Method 514.5 Procedure I, Category 20, Fig 514.5C-1, the notebook's processor, graphics, memory and HDD/SDD are being accessed.

Temperature

     Temperature is a key measurement of ruggedness for law enforcement. Temperatures in a closed vehicle during a typical summer day can easily reach 140 degrees Farenheit. This high temperature can not only damage the HDD or processor, it can destroy displays and plastic components such as keyboard keys and palm rest areas. At the opposite extreme, cold temperatures can impact HDDs and displays and make plastic components brittle and more susceptible to damage. Fortunately, the MIL STD includes several tests that are designed to replicate these extreme conditions. When purchasing a notebook for any vehicle deployed workforce, make sure they have been tested to these standards:

  • MIL-STD 810F, Method 501.4, Procedure II (Operating): notebook will survive and function at 140 F.
  • MIL-STD 810F, Method 502.4, Procedure II (Operating): notebook will survive and function at -20 F; start-up from -20 F without causing damage; and the screen is viewable and functional, as many displays lose brightness and speed at low temperatures.

Dust

     Law enforcement officers often have to drive at high speeds, and inevitably dust gets into the cab of the vehicle and can cause shorting inside the notebook. There are two tests that can be performed that provide assurance a notebook can withstand exposure to dust: IP5x:IEC 529 (en60529) (IEC60529) and MIL-STD-810F Method 510.4 Procedure I (Dust).

Liquids

     Since most law enforcement officers rarely, if ever, need to use their notebooks in the rain, purchasing a unit that is rain proof can be excessive and therefore cost you more money. Instead, focus on typical events that may occur inside a vehicle, and how an officer would respond.

     First, consider what type of liquid is most easily spilled onto a notebook. Most likely it will be some sugary/sticky drink, such as coffee, cola or energy drink.

     Second, determine how much liquid might be spilled onto a notebook and how much is likely to remain on the unit, as opposed to how much would fall between the seats and onto the console area.

     Third, determine how long it would take an officer to locate a safe place to pull over, undock the notebook, open the door and pour out the remaining liquid. Lastly, how would the notebook be cleaned off, now that it has sugar underneath the keyboard keys?

     A test to simulate this event should require that the notebook continue to operate; involve at least 12 ounces spilled directly on the keyboard, touchpad and palm rest area; allow for an appropriate soak time (time it takes an officer to get liquid off the unit); and a cleaning method that does not require the notebook to be returned to the factory.

     One of the keys to this test is the time element. Seals, when saturated, can become porous and begin to allow liquid to pass into the notebook. Make sure that the notebook you select can withstand liquid on the unit for at least 10 minutes.

Impact resistance

     Better known as drop protection, since most officers will only take their notebooks out of their vehicles a few times a day (to go into a facility and capture information or to write reports, for example), the chances of dropping a notebook are significantly lower for law enforcement officers than for war fighters, utility workers or even office staff who take their notebooks from office to meeting room countless times a day.

     To ensure a notebook can survive several drops and multiple impacts, make sure it has been tested to MIL-STD 810F Method 516.5. This includes six 30-inch drops to simulate an officer dropping the notebook onto a hard surface while carrying it to and from the vehicle.

     While some notebooks provide greater drop protection, it comes at a significant cost and can easily lower your total cost of ownership, as you will most likely be purchasing protection you do not need.

     The tests outlined here are designed to help establish the criteria that best simulates your workforce. Choosing less rugged can cost more over time while choosing too rugged can cost more up front.

     Tim Hill, product marketing manager for General Dynamics Itronix, has more than 20 years experience in both the telecommunications and rugged notebook computer markets.

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