Optical density Specific optical density

ABSTRACT: In this study, we examined smoke generation from red oak and Douglas-firply wood using the National Bureau of Standards (NBS) smoke density chamber in the smoldering mode at 2.0, 2.5, and 3.0 W/cm2 of heating flux. The data included optical density and partic ulate (soot) mass concentration, both as a function of time and heating flux. Data from the NBS chamber were compared to data from a dynamic smoke measurement apparatus, the Ohio State University (OSU) calorimeter. Because of basic differences between the NBS cham ber and the OSU apparatus and between the units of measurement used in these methods, the results were reduced to a common unit, particulate mass per unit area of exposed specimen surface. Comparison of the data at 2.5 W/cm2 of heating flux showed reasonable agreement. KEY WORDS wood smoke, smoke optical density, particulate concentratio