Dependable gas detection without heated mirrors

Featuring dual-wavelength IR sensor technology in a rugged 316 stainless steel package, IRmax is designed to detect methane gas and other potentially explosive hydrocarbons in the harshest conditions.

Unlike conventional IR gas detectors, IRmax does not utilise heaters to prevent condensation on windows and mirrors. Instead, its optical components are treated with a highly durable hydrophobic coating called STAY-CLIR that completely prevents signal faults due to condensation.

IR type gas detectors detect tiny reductions in transmitted infrared energy due to absorption by molecular resonation in hydrocarbon gases and vapours. It is essential that the light path of the detector is not obscured by condensation or dirt to ensure dependable hazard detection. Conventionally, the windows and mirrors in IR detectors are heated to prevent condensation forming. Although an effective solution, heating components require significant amounts of power to operate and can result in the build-up of dissolved deposits (such as salt).

As IRmax contains no components for artificially heating optical surfaces, power consumption is dramatically reduced. It requires less than 1 Watt of power, typically 75-90% lower than conventional IR gas detectors. A gas detection system using IRmax detectors therefore requires smaller (and lower cost) power supplies and battery back-up systems. Longer cables can also be used and more detectors can be powered on addressable networks.

A further benefit of the STAY-CLIR coating is resistance to contamination from dirt and dust, rendering routine cleaning of the optical components unnecessary.

IRmax is Crowcon’s third-generation IR gas detector, and the 15 years of experience with previous IR products guided the products’ design and development. A key design goal was to find an effective alternative to heated optics whilst retaining long-term dependable operation with minimum maintenance.

Specialised coatings are well established for use on a myriad of products, from footwear to mobile phones, but Crowcon is the first company to apply the technique to gas detection with the intention of completely removing heaters.

Detailed research and development was undertaken by Crowcon’s scientists, resulting in a highly durable coating that was proven by being subjected to aggressive corrosion and resilience tests in extreme locations such as the Australian desert and the north coast of Scotland. The tests included:

• Long-term immersion in salt-water
• Long-term immersion in vessels filled with sulphur, hydrogen sulphide and sulphur dioxide
• Direct exposure to continuous sand-spray
• Continuous rubbing to simulate excessive cleaning
• Long-term site trials on offshore platforms, petrochemical plants and sulphur recovery plants

IRmax has been continually in use on petrochemical sites from the North Sea to Singapore since September 2009, providing ‘real world’ evidence of the effectiveness and durability of the STAY-CLIR coating.

About Crowcon

Crowcon (www.crowcon.com), a subsidiary of Halma p.l.c. (www.halma.com), is a world leader in portable and fixed gas detection instruments. The company is based in Oxfordshire in the UK and has branch offices in the Netherlands, the USA, Singapore and China. It specialises in developing, manufacturing and marketing innovative, reliable and cost-effective flammable and toxic gas detection equipment and has constantly led the field with products designed for safety and environmental monitoring.

More information IRmax ultra-compact infrared (IR) gas detectors

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