Absolute Temperature and Emissivity Determination of Flame-Heated Materials Using Multispectral IR-Imaging and 2-Band Ratio Pyrometry

Monitoring temperature of critical components in the extreme environments found within experimental fusion reactors presents a unique challenge. Typical contact-based temperature measurement devices such as a thermocouple require the placement of components on the surface to be measured, requiring exposure to the extreme conditions within the plasma vessel as well as potentially disturbing production and maintenance of the plasma itself. Non-contact temperature determination techniques such as two-color pyrometry avoid these issues but are limited to point measurements. Telops is developing a 2-band ratio-pyrometry algorithm that extends point-based two-color pyrometry principles to calculate the absolute temperature and emissivity of a multispectral thermal infrared image on a per-pixel basis.

In this work, the Telops MS-M350, a multispectral infrared camera equipped with a fast rotating, 8-position filter wheel was used to collect IBR data on flame-heated materials for preliminary investigations of algorithm performance. Satisfactory temperature and emissivity separation is achieved for static scenes including the back face of a flame-heated steel plate and a structural composite material.