Automated infrared imaging temperature measurement with application to upward flame spread studies. Part I

Abstract

This article describes a new experimental technique with wide application that has been proven for wall fires. To measure the spread rate of the pyrolysis front along vertically oriented flat and corner walls, it may be necessary to measure transient temperature profiles on the walls. Conventional thermocouple and visual observation methods, however, have limitations due to complexity of implementation and the inherent ambiguity of visual observations due to interference from flames. To overcome these limitations, an automated infrared imaging system was applied to obtain two-dimensional wall surface temperature data in a relatively large area. In addition, upward flame spread experiments were conducted over vertically oriented PMMA flat and color board corner walls; and surface thermocouple and infrared imaging temperature data were compared in the PMMA wall fires. All the results indicate that the infrared system with a (10.6 ± 0.5 μm) bandpass filter successfully avoids interferences from the flame allowing measurements of temperature distribution on the fire-heated wall, from which the spread rate in any direction can be deduced. However, this technique will fail for flames whose emissivity is greater than 0.1.