Understanding ignition sources and levels of device protection are crucial to reducing risk.
By Justin Olivier, Product Manager, Mobility, Pepperl+Fuchs, Inc.
Mobile devices can solve many challenges in hazardous industrial environments — from monitoring lone workers to enabling predictive maintenance to streamlining field support. But a device that lacks the proper protection could seriously compromise the safety of your plant and personnel. Even something as simple as a hot surface on an unprotected device can have disastrous consequences.
It’s important to recognize ignition sources from mobile devices. Even when unprotected mobile devices are turned off, ignition is possible. Examples of this include:
- A battery short circuit in an unprotected device.
- A loose battery in an unprotected device.
- Electrostatic discharge — for instance, from pulling an unprotected device out of a holster.
Other typical ignition sources include:
- Hot surfaces and open flames.
- Electrical arcs and sparks.
- Mechanical friction or impact sparks.
- Electromagnetic and optical radiation — such as from radios or barcode scanners in an unprotected device.
Intrinsically safe mobile devices help safeguard that these potential ignition sources are removed or prevented. But to prevent the risk of explosion, it is not enough to select just any protected device.
It’s also important to determine what kind of testing and Zone/Division approvals your devices include. The ratings help verify your device is safe for use in hazardous areas.
Zone and Division Testing and Certification
Zone/Div. 2 devices are tested only for the above-listed ignition sources under normal conditions — not if the device develops a fault. Zone/Div. 1 devices, on the other hand, are tested in both normal and fault conditions.
Further, the batteries in Zone/Div. 2 devices are not tested for temperature increase under short-circuit conditions. Only Zone/Div. 1 devices are designed so temperatures remain low enough to prevent an ignition. In short, Zone/Div. 1 devices are subjected to more stringent tests under both normal and fault conditions.
Answer the questions in Figure 1 to help determine whether the smartphones, tablets, scanners and other mobile devices in your plant are putting personnel, assets and the environment at risk.
The Right Mobile Devices
Using the wrong mobile device creates an enormous amount of risk. To reduce this risk, follow these basic steps:
- Use the correctly certified and marked devices in hazardous areas.
- Select manufacturers with a proven track record of delivering mobile devices for use in hazardous areas.
- Do not compromise on safety. Always consult safety and certification specialists.
Pepperl+Fuchs, Inc, Twinsburg, Ohio, is an Encompass™ Product Partner in the Rockwell Automation PartnerNetwork™ program. The company supplies automation equipment for explosion protection for the process industry, including intrinsic safety isolators, Zener barriers, signal conditioners, fieldbus technology, remote I/O, HART interfaces, level measurement, purge and pressurization systems and more.
The Journal From Rockwell Automation and Our PartnerNetwork™ is published by Putman Media, Inc.