Infrared thermography and calibration techniques for gas turbine applications: a review

Abstract This paper presents a comprehensive review of the calibration techniques for infrared (IR) measurements in the field of gas turbines. When performing IR thermography in challenging environments, such those of gas turbine experiments, particular attention must be paid to (i) the target emissivity, function of temperature, surface conditions and observation angle, (ii) the surroundings reflected radiation and (iii) the optical pathway transmittance. This review study aims at understanding and describing how the aforementioned sources of error affect the measurement accuracy when using pyrometers and IR cameras. Many developments and recent advances are presented, including numerous calibration methods and advanced image processing techniques. The relative strengths and limitations are outlined by comparing past studies in the literature. The results will help to identify a methodology for future researchers to improve the IR measurement accuracy for gas turbine experiments. The fundamental understanding of the measurement error contributions is also applicable to other research fields.