Dielectric and optical evaluation of high-emissivity coatings for temperature measurements in microwave applications

In this work, several commercial high-emissivity coatings have been characterized in terms of emissivity, chemical composition and dielectric properties as a function temperature, under microwave irradiation. Accurate knowledge their response exposure to microwaves provides new crucial information about practical usability for non-contact temperature measurements environments. Due high metallic content, some the studied exhibited unexpected microwave-triggered reactions that hindered use up maximum specified by manufacturers. Emissivity analyses before after heating cycles confirmed degradation samples predicted measurements. This work illustrates how careful characterization optical representative operating conditions (temperature range, exposure) is vital order select appropriate reference coating obtain reliable applications.