Laser scanning heating method for high-temperature spectral emissivity analyses

• New method for non-contact heating of samples for emissivity analyses.
• Solution to reach high temperature in the range 300–1200 °C.
• Solution to reach homogeneous temperature field within units of °C.
• Applicability for various sample shapes and dimensions.

A new non-contact laser heating method for the normal spectral emissivity measurements of high-temperature coatings is introduced. The method utilizes laser source in combination with scanning optics. General and specific requirements for the method development are discussed. Works on the development of the optimal heating strategy to ensure homogeneous temperature field of the area for the emissivity analyses on the sample surface are summarized. The final experimental set-up and heating procedure are described in detail. Advantages and disadvantages of the method and the method applicability are also discussed. The experimental set-up with 400 W laser is capable to heat steel substrate samples in the range of 300–1200 °C. Temperature transition of about 100 °C takes about 300 s. Temperature homogeneity in the area measured by spectrometer is within 2.5 °C in the whole temperature range.