Infrared Thermography 1: Optical & Physics Fundamentals

Infrared (IR) thermal imaging, thermography, thermology, thermal wave imaging, thermovision and thermal infrared night vision use thermal imagers or Infrared imaging cameras. These devices sense infrared radiation energy and convert it to images we can see. IR imaging devices collect photon energy from the radiation and convert it to an intensity or illuminating value for small areas like pixels on a TV or PC screen. These are then displayed as images on an LCD display screen or a similar screen. A thermographer uses the images in conjunction with his or her understanding of thermodynamics, heat transfer, and how building systems function to look for anomalies. Anomalies of IR emission are sought as they can reflect differences in materials of use, thermal conductivity, IR reflectivity, IR emissivity, moisture, etc. which can both reveal and reflect poor building material performance, e.g., damaged or missing insulation. The ability of an IR camera will depend on a series of factors that will be demonstrated including minimum resolvable temperature difference (MRTD), minimum detectable temperature difference (MDTD), noise equivalent temperature difference (NETD; NEΔT), and Field of View (FOV).