Considerations for Uncertainty Within Absolute Temperature and Emissivity Measurements Accessible Though the Application of Two-Color Infrared Pyrometry

Two-color pyrometry has been demonstrated utilizing non-contact, high temporal-resolution multispectral infrared imaging data for the retrieval of absolute temperature and material emissivity of both high-temperature and actively combusting materials. This is particularly useful within Tokamak reactors and other plasma containment vessels, within which extreme conditions limit opportunities for direct measurement techniques. Telops’ multispectral imaging systems are well suited for this task as narrowly spaced spectral bandpass filters can be selected strategically to omit radiation expected from known combustion gasses. This allows the collected imagery to observe thermal emissions originating solely at the surface of interest.

Pyros, a two-band ratio pyrometry algorithm developed by Telops and Polytechnique Montreal has proven effective in conducting such analysis, and uniquely, does so on a pixel-by-pixel basis within sequential frame images, though error considerations remain broad and further development is needed. This work will address key sources of uncertainty within the Pyros algorithm, including differences observed when imaging combusting and non-combusting surfaces, the critical nature of temporal resolution, and spectral bandpass considerations. As a further development, an ongoing measurement campaign will be discussed which aims to utilize multiple multispectral systems simultaneously, with cameras synchronously imaging both the combusting and non-combusting surface of a single sample.