IgorsLAB published How we test with thermal imagers: Infrared technology explained and how to use it correctly A quote from the article:

In many basic articles I have already conveyed the theoretical basics and some background information on the correct use of infrared technology for years, without, however, going into more detail about the concrete application in my measurements. Five years ago, I then presented the current technology, although this article is still valid today.

  How we test with thermal imagers: Infrared technology explained and how to use it correctly