Infrared thermography

Infrared (IR) thermography is a no-contact technique for measuring the surface temperature of a body or an object. The Infrared camera is equipped with an optic for infrared and a detector which analyses the wavelength of the emitted light. Light has three variables:

  1. luminous intensity, determined by the amplitude,
  2. colour, determined by the frequency or wave length
  3. polarisation, determined by the direction of the vibration.

The frequency or wave length of the light emitted by an object can be used to determine its surface temperature, making it possible to determine the temperature of an object using a colour spectrum (thermography). IR themography is mostly applied in industry, electrical engineering and in the built environment, for example for security purposes, localization of fires, detection of missing persons and the detection of heat losses and overheating on high voltage pylons or power plants, often indicators for damage to or future failure of insulation material.

How does it work?

An IR thermography camera produces a thermogram, a visual representation of the temperatures of the object, with different colours representing different temperature ranges. In most cases low temperatures are represented by dark colours and high temperatures by lighter ones.

Various parameters are linked to a thermogram, some of which strongly influence the results. For example the emission value, reflectivity, humidity and the type of camera used. The camera provides information on the resolution of the detector, IFOV (Instantaneous Field of View) and the temperature range. Other important parameters are linked to the scope of the thermographic measurement. The best results are achieved in cases with temperature differences of at least 10 degrees Celsius between the object and its environment. This makes winter the most suitable season for drone IR thermography in the open air.