Safer by design

Rama Oruganti on designing intrinsically safe wearables for the oil & gas industry.

Oil rigs, chemical plants and refineries are among the world’s most hazardous working environments. Equipment employed in these worksites prioritise worker safety above all else. Conventional electrical gear often falls short of the safety requirements, as a single spark from a component could trigger a catastrophic explosion. Therefore, Intrinsically Safe (IS) measures are indispensable for the safe operation of electrical equipment in these volatile zones.

IS is the formal design approach aimed at making electronic equipment safe and suitable for use in hazardous zones. The technique is based on limiting energy, electrical, and thermal levels to below the thresholds that could cause combustion.

Building an IS Device for Oil & Gas

Developing an electronics device is a demanding endeavour due to numerous requirements that need to be balanced. Designing and certifying an IS device magnifies these challenges. 

There are many authorised agencies that certify intrinsically safe equipment. The European certification is called ATEX; the North American standard is the NEC500, which can be applied for through UL, FM, CSA or QPS, for example. A procedure for the certification of electrical equipment across the globe is called IECEx. Equipment employed in hazardous locations should be certified by one of these reputable systems or agencies.

Benefits of IECEx

IECEx is a voluntary system which provides an internationally accepted means of proving compliance with IEC standards.

Due to varying standards across countries, “Ex” equipment often needs to be retested and recertified to the appropriate standards of that country, adding to the cost and to the time to market for the equipment.

IEC standards are used in many national approval schemes and, as such, IECEx certification can be used to support national compliance, usually eliminating the need for additional testing. This makes international trade easier, quicker and more cost-effective. IECEx has a public online database (iecex.com) and strict control mechanisms. IECEx certification can also be seen as a seal of approval.

A device that is designed for areas where flammable vapours are present is designated with an NEC500 Class 1, Div 1 certification and an ATEX Zone 1 device. These certified devices can be used in environments where an explosive atmosphere, consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist, is likely to occur under operations. Accurate designation is extremely important for worker safety reasons. Failing to correctly designate a product can result in severe damage to both facilities and resources, an injury or fatality, and bring about legal ramifications or other risks. This certification is awarded only after thorough and rigorous checks by experienced, independent third parties. It can often take months to certify, with multiple design reviews and changes along with extensive device testing. In addition, only a few labs globally have the ability to provide the certification which adds to the time needed and complexity.

Manufacturing an IS product and certifying it to be used in hazardous locations across the world is a challenging task for the original equipment manufacturer (OEM). RealWear works with industry experts such as i.safe Mobile that incorporate international standards into product development and are also members of relevant standards committees. To fulfil requirements for explosion protection, products are developed from the ground up, so users all over the world can be sure they are using equipment that is fully compliant with current standards.

Design challenges

Now that the the definition of IS has been tackled, let’s discuss the challenges that were surmounted in developing RealWear’s latest wearable product, the Navigator Z1, an advanced hands-free IS wearable.

Compounding the IS challenge previously discussed, the company wanted the device to be modular, without needing dangerous tethering or wiring to a phone, while remaining hands-free and voice controlled. The team planned to build on the strengths found in the original HMT-1Z1 IS device. The around-the-head “horseshoe” form factor ensured the product’s weight is balanced and comfortable to wear, especially with the wide variety of safety helmets used in the field.

Making this shape also IS (as opposed to a much more common rectangular mobile phone or tablet) was a massive undertaking. For instance, fitting the electronics in the Navigator Z1 required many more circuit boards and unique wiring (Imagine building a mobile phone in the shape of a horseshoe). The device must accommodate one’s head and movement, so it must bend, rotate and flex in multiple directions, even after multiple years of rugged use.  RealWear expects such a device to be used for about five years. Part of testing the device involves subjecting it to the harshest conditions that it could face during its lifetime, including impact, heat, cold, humidity and more.

The device is to be designed to take that beating and still function flawlessly. It must also improve on the original lineup (i.e. HMT-1 and HMT-1Z1, respectively) by increasing compute power and introducing AI Core, the most powerful processor ever in a RealWear device using the powerful Qualcomm 6490 chipset, which is active until 2036 as part of Qualcomm’s extended life programme) - designed for on-device enhanced AI experiences).

The company aimed to make frontline workers more productive and safer by reducing weight and introducing the concept of modularity, as mentioned. It wanted the battery and camera module to be integrated yet removable; that is, swapped out outside of the zone.  This had never been done before. Finally, it had to maintain or even improve on the rugged standards required by industries such as oil and gas.

Understandably, an IS product must go through a rigorous set of tests put forth by experts in the field of safety.  Due to the success of HMT-1Z1, RealWear teamed up with i.safe Mobile for the second time.

In summary, the requirements for RealWear Navigator Z1 were as daunting as they sound – the team wanted to develop it as something users would have in their digital toolbox for years to come. The modular approach allowed components to be upgraded or to offer a specialised function and return on investment. The team also wanted it certified not only in zone 1 (gas), zone 21 (dust) but also for mining use. The headset needed to be lightweight, rugged, powerful and modular – all while still achieving intrinsical safety certification.

A Cautionary Note

It’s worth noting that not all IS devices are created equally. In fact, RealWear has observed several products being advertised as IS that don’t carry certifications and verification. This is a safety concern and it’s important to request certification details from vendors and ask the appropriate questions up front. RealWear is currently pursuing multiple certifications that will be announced in 2024 to ensure it can offer frontline workers the best standard in IS technology.

Rama Oruganti is chief product officer at RealWear.