Thermal Imaging Basics


Light is basically divided into two categories for the purpose of thermal imaging, visible light and invisible light. There is an almost infinite range of light beyond human range of vision. Light, as described in physics, is an electromagnetic wave that propagates through space at a fixed speed. This wave is further identified by its wave length, frequency and energy. As displayed below the actual wavelengths visible to the human eye is quite small.


Electromagnetic Spectrom


As shown by the above graphic, human only see light in the wavelength range from 400 to 750 nm (nanometers). X rays and Gamma rays were initially thought to be particle rays rather than light rays, hence the terms rays. Radio waves are an example of low-energy light waves, and they are often described in terms of their frequency.


A prism placed into a ray of sunshine in a dark room reflects the colours of the rainbow using a property known as dispersion. This is the method Sir William Herschel utilized in the 1800’s in conjunction with thermometers to discern the presence of invisible light rays. He called his discovery the “thermometric spectrum” later to be known as infared.


This is the beginning segment of Thermal Imaging….more to come



Leading and Innovating in the Home Inspection Field, call the Barrie Home Inspector when purchasing your next property.