Explosion Protection Tuning in on Explosion Protection: Wireless Equipment in Ex–Zones

Author / Editor: Stephan Schultz* / Dominik Stephan

Explosion-protected antennas restrict flexibility of radio systems — Explosion protection and wireless applications typically don't go well together. Especially the available antennas and connectors restrict the flexibility of radio systems in hazardous atmospheres. Now, a new isolator provides intrinsically safe connections for demanding tasks.

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(Picture: © Denis Junker - Fotolia)

In order to prevent the ignition of an explosive atmosphere, radio components for use in Atex zone 1 are usually enclosed in special protective housings. This applies not only to the electronics of radio components, but also to the external antennas required in most cases. However, suitable wireless transmitters with explosion-protection certifications are expensive and only available in a limited range of types.

Also, they often depend on fixed cables without plug connectors that complicate installation and maintenance work. Still, reliable radio communications require the right antenna for specific requirements.

Overcoming the Disadvantages of Wireless Solutions

Now R. Stahl, a company specialised in explosion protection, presents a solution that overcomes many of the disadvantages of conventional configurations with its new type 9730 HF Isolator. The device converts the normal antenna signal to an intrinsically safe (Ex i) signal. This signal can therefore pass through a hazardous atmosphere without any risk of causing an ignition.

Consequently, system designers can draw on the entire range of industrial antennas and plug connectors on the market – there is no need to limit the choice to components with explosion protection certification.

The HF Isolator tolerates rough conditions with ambient temperatures ranging from –60 °C to +80 °C. Using the ISM frequency bands around 900 MHz, 2.4 GHz, and 5 GHz, the HF Isolator supports all wireless transmission standards commonly applied in industrial environments (like Wifi 802.11 a/b/g/n; Wireless Hart; ISA 100.11a; Bluetooth; Zig Bee; Enocean).

Enter the Internet of Things

Industrial radio communication enables entirely new, more economic routines. This includes for example using wireless scanners to read barcode labels or RFID tags on drums, tanks, IBCs, and other containers. Wireless data transfer facilitates installation, commissioning and maintenance, allowing personnel to not only keep an eye on crucial process data, but also comfortably access maintenance schedules, user manuals, or Atex and other certificates. Service calls can be issued directly to support staff carrying mobile devices.