Thermal Imaging - Here's how it works: 
 
A special lens focuses the infrared light emitted by all of the objects in view.

The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram. This information is obtained from several thousand points in the field of view of the detector array.

The thermogram created by the detector elements is translated into electric impulses.

The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display.

The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.

Thermal Imaging - Here's how it works: 
 
A special lens focuses the infrared light emitted by all of the objects in view.

The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram. This information is obtained from several thousand points in the field of view of the detector array.

The thermogram created by the detector elements is translated into electric impulses.

The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display.

The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.

 

Thermography or thermal imaging, refers to the process of recording the emission or existence of thermal or infrared radiation (heat), by employing the use of a thermal imaging device or infrared camera, sometimes referred to as an "IR". Although thermal imaging can be used in the daylight, thermography allows one to "see" in the dark as it does not rely of the reflectance of light within the "visible" range of the Electromagnetic spectrum in order to record imagery. All objects at temperatures above Absolute Zero ( 0 K or -273.15 °C) emit some sort of thermal radiation, many within the infrared portion of the Electromagnetic spectrum.

Thermography refers to the wavelengths within the spectrum in units of nanometers, micrometers, or microns. The commonly referred to ranges within the spectrum are gamma rays, x-rays, uv rays, visible, infrared (IR), microwave, and radio. Some objects that are very hot (such as the Sun) emit thermal radiation viewable within multiple parts of the EM spectrum such as the "visible", the "ultraviolet" (UV) and the "infrared" areas.

What is Thermography used for?

Thermography is employed in many areas. Building diagnostics, non-destructive testing, military, maintenance, law enforcement, security, veterinary, medical, as well as astronomy are just are few of the areas where thermography is used to identify or diagnose potential problems. Thermal imaging is also used in infrared satellites to monitor the Earth's weather & vegetation patterns.

In the medical arena, thermography is actually referred to as "thermology" although "thermal imaging" is often heard (as in the term "thermal imaging lab".

The following is a list of thermal imaging terms or "therminology" that one might hear when referring to the use of thermography: