Thermography and the detectors that make it work

“Ultimate” is a risky tag to assign to one's literary efforts, and an infrared (IR) expert might not think a 40-page book could warrant that tag. But for those of us with a passing familiarity with IR technology, or for beginners just getting involved in IR inspection applications, this short book provides a wealth of valuable introductory information as well as specific information you can apply on the job.

Chapter 1 begins by defining the IR range (900–14,000 nm) and relates an IR camera's operation to that of a digital video camera, with a focal-plane array implemented in thermal (microbolometer) or quantum detector technology. It proceeds with a background on blackbody radiation, Planck's law, and Wien's displacement law, leading to a description of how to derive temperature when given factors such as an object's emissivity, atmospheric attenuation, and ambient temperature.

Subsequent chapters cover topics such as filters, detector types, high-speed thermography, and how to make the most of your IR camera. Chapter 2, for example, provides details on quantum detectors, which respond to IR inputs by elevating electrons in the detector material to higher energy states. Of these types, the book notes, InSb and quantum well infrared photon (QWIP) types offer high sensitivity, detector uniformity, and relatively low cost.

Chapter 3 provides information on spot and area temperature measurements, emissivity correction, and camera specs. Filters, chapter 4 notes, can be useful for materials that are transparent or opaque to IR wavelengths. Chapter 5 describes high-speed applications, such as temperature measurement of a 0.30-caliber bullet in flight.

The book includes a table of FLIR products as well as about five pages of advertisements, including one from this magazine and a competitor.

The Ultimate Infrared Handbook for R&D Professionals, www.flir.com.