Understanding Infrared Thermography Reading 3

40.Fiber optic, infrared - A flexible fiber made of a material that transmits infrared
energy, used for making noncontact temperature measurements when there is not
a direct line of sight between the instrument and the target.
41.Filter, spectral - An optical element, usually transmissive, used to restrict the
spectral band of energy received by an instrument's detector.
42.Focal plane array (FPA) - A linear or two-dimensional matrix of detector elements,
typically used at the focal plane of an instrument. In thermography, rectangular
FPAs are used in staring (nonscanning) infrared imagers. These are called infrared
focal plane array imagers.
43.Focal point - The point at which the instrument optics image the infrared detector at
the target plane. In a radiation thermometer, this is where the spot size is the
smallest. In a scanner or imager, this is where the instantaneous field of view
([FOV) is smallest.
44.Foreground temptrature (see instrument ambient background) - Temperature of
the scene behind and surrounding the instrument as viewed from the target. (See
Figure A-1.)
Charlie Chong/ Fion Zhang