GRP enclosures aid migration to wireless instrumentation networking

INTERTEC offers a wide range of protection possibilities

Intertec has long been aware that one of the many benefits of its GRP composite material is electromagnetic transparency – it produces a wide range of frangible environmental protection cabinets and shelters for radar and instrument landing systems at airports which are designed not to reflect or interfere with radio signals. The housings are also used extensively for cellular and satellite communications applications, as well as satellite navigation systems; the GRP material causes no measurable loss of received or transmitted RF signals, so the equipment antennas can be contained within the enclosure. However until now, Intertec has not actively promoted the fact that the non-metallic construction of its products is also ideally suited to field-based 2.4 GHz wireless sensor networks, especially for applications where external antennas are inadvisable because of their susceptibility to accidental damage.

A number of Intertec''s customers, as well as manufacturers of wireless process monitoring automation, have started to evaluate the electromagnetic performance of its GRP-based enclosures for housing field-based WSN equipment. Initial results are very promising: third-party tests involving a WirelessHART gateway and a WirelessHART field device, both with built-in antennas and sited in different rooms, found that when the field device was placed inside a standard Intertec instrumentation enclosure it continued to function properly, with no measurable loss of signal.

The tests were conducted using a model from Intertec''s Multibox range, but the same results are likely to be obtained from many of the company''s enclosures that use similar construction.