Tough inside and out

What makes a rugged device robust in a multitude of environments? James Mann at Getac UK Ltd gives us the lowdown

Millions of people around the world have jobs that regularly take them outside the safety of the office and into environments that pose challenges from a technology perspective. From industrial manufacturing technicians on the factory floor to paramedics at the scene of an incident and service engineers out in the field, they all need devices they can rely on, whatever the situation throws at them. 

Unfortunately, most consumer-grade laptops and tablets are not built to operate in these kinds of physically challenging conditions, meaning a knock, or rain drop can quickly lead to device failure.

For this reason, a growing number of organisations are turning to rugged technology. Rugged devices are designed to deliver optimal performance in environments where knocks, drops, vibrations, high and low temperatures, moisture and dust are all par for the course. As such, they are built to a much tougher standard than their consumer counterparts, which is reflected in the materials they’re constructed from, the testing/certification processes they must go through, and the warranties that accompany them.

Survival of the fittest
When it comes to rugged product design, the starting point is durability and reliability – as opposed to shape and form factor in the consumer market. Resistance to impact, force and pressure are all key considerations but these must also be balanced against overall device weight and usability. For this reason, magnesium alloy has traditionally been the primary material used in rugged chassis construction, due to its excellent strength-to-weight ratio. However, in recent years, advances in technology has seen the use of composite plastics grow considerably, helping to further reduce overall device weight while still retaining the same level of strength and durability. 
Elsewhere, the placement of internal mounting points is important. Components are mounted securely and independently from one another to prevent a single point of failure causing total device failure. Rubber bumpers on all corners and potential points of weaknesses add further protection in the event of the device being dropped or receiving a sharp knock.

Making the grade
For a device to be considered fully rugged, it needs to go through several certification processes. The two main industry standards are ingress protection (IP) rating and MIL-STD-810 certification. Other specialist certifications, such as atmospheres explosible (ATEX) are available for devices used in hazardous or potentially explosive environments.

An IP rating determines how resistant the equipment is to the ingress of water, dust and foreign bodies. Ratings consist of two numbers, with the first digit pertaining to intrusion protection (e.g. dust) and the second digit to liquid resistance. IP65 is the industry standard for fully rugged devices, meaning a dust resistance of six (dust tight), which is full protection against dust and other particulates, and a water resistance of five, which is protection against low-pressure jets of directed water from any angle. However, some rugged manufacturers offer higher levels of protection.

The MIL-STD-810 certification consists of a series of tests designed to evaluate a product’s readiness for use in a range of extreme conditions. Originally designed by the US military, MIL-STD testing has since been adopted by non-military industries because of its thorough testing process. Although it is an American standard, issued by American laboratories, it is widely seen as the global benchmark for rugged devices. 

MIL-STD-810 tests performance in an array of conditions and situations, including high/low pressure, high/low temperatures, rain, humidity, vibration, acoustic shock, impacts and altitude, among others. The process also includes a drop test that assesses resistance to shock across all the device’s surfaces, including faces, edges and corners. In total, 26 drops from about four feet are necessary, with the device inspected after each one.

ATEX is a specialist certification for devices intended for use in hazardous environments containing flammable gases, vapours, or combustible dust/fibres, where a single spark has the potential to cause an explosion. Under the ATEX system, zones containing gases/vapours are assigned a rating between 0 – in which an explosive mixture is continuously present or present for long periods, and 2 – in which an explosive mixture is not likely to occur in normal operation and, if it occurs, will exist only for a short time. Similarly, zones containing combustible dust or fibres are rated between 20 and 22, based on the same criteria. 

Each ATEX level contains corresponding guidelines on the safety measures that electronic equipment must incorporate in order to achieve certification for use in that zone. For example, a device certified for zone 0/20 requires much more stringent safety features than those required for use in zone 2/22.

While manufacturers are allowed to self-certify devices for zone 2/22, any device intended for use in zones 0/20 or 1/21 must be certified by an independent laboratory.

It comes down to selecting the correct rugged hardware to ride out a particular storm.