Infrared windows: the design scope is huge

Paul Boughton

Designers of electrical panels and electro-mechanical systems are embracing infrared windows with open arms. Martin Robinson explains reasons for this.

Giving a competitive edge to the product you design isn't all about increasing performance. Adding to its value can often be equally effective. Take maintenance for example. If you are a designer of electrical or mechanical systems, you can really make your mark by helping customers to get the very best return on their investment by introducing measures that allow effective and safe predictive maintenance. Indeed, this is a trend the infrared windows specialist, IRISS, is experiencing worldwide.

The growing need in the industry to keep critical systems working optimally is a key driver. Loss of service or production is costly. Such problems will ultimately compromise reputation and shareholder value. Consequently companies are introducing comprehensive predictive maintenance programmes to detect faults before they become failures, a step that is also demanded by the insurance industry seeking to minimise its risk.

Thermal imaging has emerged as the perfect technology for this detective work but, to keep the thermographer safe, stringent rules must be observed. 'Keep it closed' is now the best practice when inspecting energised systems. However, to do the job effectively, direct measurements need to be taken, allowing faulty components to be identified and the status of their criticality assessed so those in imminent danger of failure can be prioritised for repair.

Safe, live inspection

By installing IRISS infrared windows, operation-critical components can be easily monitored by the thermographer without any danger of him or her being exposed to energised equipment. In essence, an IRISS window is a data collection point that enables the predictive maintenance process to be conducted quickly and effectively. Crucially, it also allows high voltage systems to be inspected regularly, a task that is often neglected by many companies simply because human risk prevents it. But they do so at their peril as a failure in these systems could be the most costly of all.

The greatest spur to the take-up of IRISS windows is however the technology itself. Although infrared windows have been available for many years, their design and scope of application has been substantially limited by their material of manufacture, fluoride crystal. Firstly this type of window carries the significant risk of breakage, especially in the presence of vibration. Even an electrician slamming an enclosure door can cause it to shatter. This presents manufacturers, particularly those in the food and pharmaceutical sectors, with a problem.

In an attempt to prolong the life of crystal windows, many are coated, but if this coating does not cover all facets, including the edges, water ingress will eventually shorten their life considerably. During this phase of degradation, their transmission value also changes making readings taken inaccurate unless the operator constantly ensures the camera is calibrated properly. Of course, each crystal window can degrade at different rates. They are also susceptible to UV damage that results in them becoming opaque, ineffective and unsafe. And then there's the problem of size. A 4-inch diameter is the absolute maximum for these products and when it comes to shape, the only choice is round.

So what makes IRISS different? IRISS uses patented polymer material that makes its products the world's only industrial grade windows. Reinforced by an aluminium honeycomb grill, they carry an unconditional lifetime warranty against breakage and are not degraded by acids, alkalis, UV, moisture, humidity, vibration or high frequency noise.

IRISS windows can also be configured to virtually any shape or size, a capability that is not achievable with crystal technology. For example, the window can be supplied to allow the inspection of an entire bus bar or multiple components in a single pass of the camera.

Originally IRISS windows were only available in opaque polymer but that changed with the introduction of Platinum. The capabilities of this range are made possible by the IRISS Poly-View System patented clear polymer. It effectively removes the only benefit that a crystal window could claim over the opaque IRISS alternative - the ability to allow visual inspection.

Platinum is now the only window available for inspection in the UV and visual as well as all three infrared spectrums. It can be used in conjunction with any brand of thermal imaging camera, assuring a fixed and stable transmission rate for quantitative and qualitative analysis.

Any shape, any size

While safe thermal inspection of live electrical systems is one of the most common applications for the IRISS range, these products are also proving ideal for checking the health of mechanical systems during operation. The ability of IRISS to supply its polymer window products in an arched or rainbow format is a real boon in this regard.

These curved windows can effectively be 'wrapped around' a bearing, pump, motor or turbine. They can also be incorporated into machine guarding, allowing the part or system to be inspected during operation and without any risk to the thermal cameraman

Martin Robinson is CEO with IRISS Ltd, Chelmsford, Essex, UK.

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