Specific Optical Density (DS)
Specific Optical Density (DS) : Means, as defined in ASTM E 662, Standard Test Method for Specific Optical Density of Smoke Generated by Solid Materials, the optical density measured over unit path length within a chamber of unit volume, produced from a specimen of unit surface area, that is irradiated by a heat flux of 2. 5 W/cm2 for a specified period of time