CMOS based high-speed camera pyrometry measurements for validation of upward flame spread modeling

This study presents the adaptation of two-color pyrometry technique to a CMOS high speed sensor. An Edgetronic SC1 high speed camera is characterized and calibrated to provide a correlation between digital pixel intensities and the physical irradiance. A radiometric self-calibration methodology relying on computing the dynamic range of the camera is applied to obtain the camera response function. Using the Planck's radiation law and calibration source data, the relative camera response is further transformed into physical function. The robustness of the calibration is verified by comparing measured temperatures to blackbody emissions and the calibration data of a tungsten halogen lamp. The measurement method is then applied to upward flame spread along Poly(methyl methacrylate) (PMMA). Measured temperatures are used to compute soot volume fraction and radiative heat flux and are shown to be consistent with previous studies.