Infrared sensors suit predictive maintenance and safety-critical tasks / European Process Engineer Magazine, [August 2006]

http://digbig.com/4mfmc
"Temperature is one of the best indicators of a fault or malfunction in virtually all electrical or mechanical equipment. However, key electrical switchgear has traditionally proved very difficult to monitor, being inaccessible within metal enclosures. Over the last decade, the accepted preventative method of reducing the risk of key electrical switchgear failure has been periodic thermal imaging, but it is not ideal."