Office of Aerospace Medicine Technical Reports
FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute
Report No: DOT/FAA/AM-80/13
Title and Subtitle: Readability of self-illuminated signs obscured by black fuel-fire smoke
Report Date: July 1980
Authors: Rasmussen PG, Chesterfield BP, Lowrey DL
Abstract: This study, using black fuel-fire generated smoke, is a partial replication of an earlier study using an inert white smoke as the obscuring agent in the study of the readability of smoke-obscured, self-illuminated emergency exit signs.
The results indicate that, within the range of sign sizes and background luminance levels studied, and under otherwise favorable viewing conditions, most of the signs were read through black smoke with optical densities ranging between 3.0 and 4.0. At two standard deviations below the means, most of the size and luminance level combinations were identified at optical densities ranging from approximately 2.5 to 3.0.
A comparison of the results with those obtained in the earlier study using white smoke, shows both colors of smoke to be approximately equal in their ability to shroud the illuminated signs. Black smoke, however, appears somewhat more effective in obscuring small details at or near the normal visual acuity threshold.
Key Words: Visual performance, Aviation safety, Postcrash fire, Emergency evacuation
No. of Pages: 12
Civil Aerospace Medical Institute
Report No: DOT/FAA/AM-80/13
Title and Subtitle: Readability of self-illuminated signs obscured by black fuel-fire smoke
Report Date: July 1980
Authors: Rasmussen PG, Chesterfield BP, Lowrey DL
Abstract: This study, using black fuel-fire generated smoke, is a partial replication of an earlier study using an inert white smoke as the obscuring agent in the study of the readability of smoke-obscured, self-illuminated emergency exit signs.
The results indicate that, within the range of sign sizes and background luminance levels studied, and under otherwise favorable viewing conditions, most of the signs were read through black smoke with optical densities ranging between 3.0 and 4.0. At two standard deviations below the means, most of the size and luminance level combinations were identified at optical densities ranging from approximately 2.5 to 3.0.
A comparison of the results with those obtained in the earlier study using white smoke, shows both colors of smoke to be approximately equal in their ability to shroud the illuminated signs. Black smoke, however, appears somewhat more effective in obscuring small details at or near the normal visual acuity threshold.
Key Words: Visual performance, Aviation safety, Postcrash fire, Emergency evacuation
No. of Pages: 12
Last updated: Friday, June 1, 2012