09 June 2008
Stuart Scott

The growth of mobile computers has added a new level of complexity to protecting workers in warehouses and logistics organisations that store or transport combustible goods.

Changing safety, security, regulatory and reporting requirements are pushing businesses towards more sophisticated systems to monitor and manage a variety of work environments.

Portable computers can be important components of these systems because they allow operators to collect and communicate data from remote and challenging environments. But confusion over regulations and certification regimes has led some organisations to conclude incorrectly that they can't use mobile computers to support maintenance, monitoring, data collection and other activity where there are combustible gases and liquids.

Much of the confusion centres on the terms "intrinsically safe" (I-safe) and "non-incendive", which have different meanings.

Non-incendive generally means the device does not generate sparks and is incapable of igniting gases, vapours or liquids under normal operation. Non-incendive devices are not necessarily sealed against gases, vapours or liquids.

According to the International Electrotechnical Commission (IEC), non-incendive devices are: "a concept in which any arc or thermal effect produced under intended operating conditions of the equipment is not capable, under specified test conditions, of igniting the flammable gas-air mixture."

Intrinsically safe indicates a higher level of safety and protection. Devices designated as intrinsically safe will not spark or cause ignition of an explosive environment. The IEC defines intrinsically safe devices as "not capable of causing ignition of a given explosive gas atmosphere."

No category errors

Organisations also need to understand ingress protection (IP) ratings. These apply primarily to device enclosures and are defined by International Electrotechnical Commission (IEC) standards.

IP ratings are measures of how well a device is protected or sealed against water, moisture, dust, powder and other substances, and are designated by various letter and number codes.

Ratings are typically expressed by the letters IP followed by two numbers. The first number indicates the device's level of protection against particles, and the second digit is the protection against water. For example, a mobile computer rated IP54 has level five particle protection, which means dust deposits may form on the unit but will not affect performance, and level four water protection, which means the device can function when splashed or exposed to low-pressure spray.

Importantly for storage and logistics companies that handle potentially dangerous goods, intrinsically safe and non-incendive standards apply to all equipment that can create one or more of a range of potential explosion sources, including: electrical sparks, flames, hot surfaces, static electricity, electromagnetic radiation, mechanical impact, acoustic energy and ionising radiation.

Intrinsically safe mobile computing devices are ideal for use in areas where workers handle unstable or dangerous goods; such as employees loading and unloading fuel at service/petrol stations, monitoring gas flow and instrumentation on a gas pipeline or managing the inventory of fuel products in a warehouse.

Intrinsically safe devices can be used in non-incendive environments, but the reverse is not true. Therefore intrinsically safe devices not only provide more protection, they provide more flexibility, because they can be used in more places.

Intrinsically safe mobile computers are also a good choice for future-proofing warehouse and logistics operations and systems because they can be used in potentially hazardous environments without having to be replaced should conditions change.

A systematic approach to managing mobile computers and wireless networks, and understanding safety certifications, allows organisations to specify products with the right level of safety for each area. The results of this approach will be a lower total cost of ownership, simplified device management and support, and - most importantly - a safer, more productive work environment.
 
Stuart Scott is director of international marketing for inventory tracking specialists Intermec Technologies, www.intermec.com

Categories:
Fire, Risk assessment, Risk assessment, Article