Computing platforms destined for use in hazardous locations (HAZLOC) require far more robust mechanical designs even relative to systems used in rugged automotive or general military & aerospace applications. But as you might expect given the broad support for Intel® Architecture (IA) processors, there are vendors that offers embedded systems for use in places like oil rigs or chemical processing plants. Indeed design teams can mix rugged panel computers and headless systems while still enjoying the benefits of the widely-supported IA ecosystem in terms of software and development tools.
Let's jump right into an examination of a recent product from General Electric Intelligent Platforms (GE)1, and we'll use some of the feature set of that product to illustrate the requirements of HAZLOC applications. GE recently introduced the Wolverine III flat-panel embedded computer that targets HAZLOC usage. As the suffix indicates the newest product is the latest in a family of rugged systems.
Prior-generation HAZLOC systems from GE have utilized Intel® Pentium® M and Intel® Celeron® processors. The new Wolverine III is based on an Intel® Core™ 2 Duo processor operating at a 2.26-GHz clock rate. The design also relies on the Intel® GS45 Graphics Memory Controller Hub IC and the Intel® I/O Controller Hub 9M (ICH98). The former integrates a graphics processor and connects to as much as 4 Gbytes of DDR3 SDRAM. The processor and support ICs all have a legacy in general-purpose mobile designs and are amenable to usage in low-power embedded systems with no active cooling.
Like most systems that target rugged applications, the Wolverine III works over an extended temperature range and is resistant to shock and vibration. The systems operates over a temperature range of -20° to +60° C. Optionally, a heater can extend the low end of that range to -40° C.
The shock tolerance is based on Mil-STD-810E – it can withstand a 40g pulse. The system, equipped with a rotating hard drive, can with stand 1g vibration over a 10- to 500-Hz range for all three axes. By specifying the system with a solid-state disk drive, you can double the vibration tolerance.
Now let's move to some HAZLOC-specific features. GE states that the design meets ATEX Zone 2 and NEMA 4X requirements. What does that mean?
ATEX is a set of European Union (EU) directives focused on equipment that might be used in hazardous environments in which explosive gases or vapors may be present. The acronym has French derivation so we won't define it here. The purpose of ATEX is to ensure that equipment including electronics can't ignite gas that may be present. Zone 2 is the ATEX level for an environment where an explosive mixture is not likely under normal conditions but in which a level of protection against explosions is still required.
NEMA (National Electrical Manufacturers Association), meanwhile, publishes a broad range of specifications for equipment and enclosures sold in the US. NEMA Type 4X focuses on enclosures that protect personnel from potential hazards within an enclosure, and that protect the equipment inside the enclosure from water including from ice on the outside of the enclosure and from dust and other elements.
GE also specs the system for compliance to IP65. The IP (ingress protection) rating is also based on the IEC 60529 standard and it defines how robust a system is to protection against hands or fingers to water from ingress into a system. The first digit, a 6 in this case, specifies dry elements including fingers and dust and 6 is the highest level of protection meaning no dust enters the enclosure. The second digit provides a rating relative to protection from water. The 5 rating is toward the top of the scale and indicates protection against jets of water.
GE says that the system enables robust human machine interfaces (HMI) in applications such as oil and gas exploration. In such environments the system may be exposed to extreme temperature, vibration, shock, ocean salt, spray, and dust.
Modular system design
The Wolverine III also has one other architectural element that is worth mentioning. The system is based on a COM (computer on module) Express module that carries the processor and chip set. The COM concept allows a system design to be updated to the latest processor over the course of an extended life for a system platform. Indeed GE says that the Wolverine III system may be upgradeable in the field going forward and certainly the COM-Express-based design will allow GE to more easily offer a next-generation system with a faster processor.
Of course GE isn't the only vendor of rugged systems or ones that can be used in HAZLOC applications. MEN Mikro Elektronik GmbH2, for example, offers such products. On example is the RC1 family of rugged systems. The company offers the systems with or without a 3.5-in display. The display is meant primarily for service purposes, and not as a screen for an HMI. The RC1 is based on an Intel® Atom™ processor at a choice of 1.1 or 1.5 GHz. The RC1 Is rated IP67 indicating that it can be immersed in water 1M deep. MEN Mikro has not specified ATEX or NEMA ratings.
MEN Mikro also offers the DC2 ruggedized panel computer with a larger 10.4-in display. That Atom-based product is specified with an IP65 rating for the front of the unit but only a IP20 rating for the rear of the enclosure.
AAEON Technology3 offers 12.1- and 15-in in panel computers that achieve an IP67 rating. The larger system is based on a 1.6-GHz Intel® Atom™ N270 processor. The smaller system offers a choice of the Atom processor or a 1.06-GHz Core 2 Duo. AAEON does not provide ATEX or NEMA ratings.
Have you designed a system for a HAZLOC application? Did you use an off-the-shelf computer or design your own system? Can you share your experience meeting ATEX and NEMA requirements with other followers of the Intel® Embedded Community? Readers would appreciate your comments.
Roving Reporter (Intel Contractor)
Intel® Embedded Alliance
1. General Electric Intelligent Platforms is an Associate member of the Intel® Embedded Alliance
2. MEN Mikro Elektronik GmbH is an Affiliate member of the Alliance.
3. AAEON Technology is an Associate member of the Alliance.