PYROMETRIC DETERMINATION OF TEMPERATURE IN RICH FLAMES AND WAVELENGTHDEPENDENCE OF THEIR EMISSIVITY

A new experimental and theoretical method is described to determine th e temperature of a rich flame from its luminosity in a time-resolved w ay. It differs from existing methods in supplying the wavelength depen dence of the flame emissivity <(epsilon)over cap>. The light emitted b y the combustion is collected by a spectrograph and an image-intensify ing streak-camera. Temperatures are derived from the spectral data. Th is pyrometric method is more precise and more meaningful than previous ones because it is free of any arbitrary assumptions on the wavelengt h dependence of <(epsilon)over cap>. The experimental scheme is relati vely simple and very well suited for various applications. It was test ed by investigating a candle light: a butane gas burner, and a series production diesel engine. It yielded temperatures with a total error o f about 4%. (C) 1998 by The Combustion Institute.