Infrared thermography is widely used to determine locally resolved surface temperatures. Research and industry alike rely on this technique when high-resolution quantitative results are required. Common applications include the analysis of thermally high loaded parts, process control, or power electronics design and maintenance. However, correct calibration can be challenging and is often neglected. An incorrect calibration leads to an undefined uncertainty, since infrared thermography does not provide unambiguous surface temperature measurements.
This chapter covers the basic theoretical foundation on infrared thermography. Simple and advanced calibration techniques for different infrared thermography systems will be presented. The chapter will focus on the data acquisition with focal plane array (FPA)-style cameras, allowing for large measurement areas and the additional flexibility provided by changeable optics. Most of the temperature calibration techniques presented are applicable to any kind of thermal radiation measurement.