抄録
The objective of this paper is to clarify the effect of spectral power distribution of different fluorescent lamps and luminance levels on the human brightness perception in a building interior. The following psychological tests were conducted. The perception of room brightness over photopic luminance ranging from 100cd/m^2 to 300cd/m^2 was measured for 20 subjects using a pair of experimental chambers. The daylight, warm white, incandescent colour 3band-type, white, 3band-type and daylight 3band-type fluorescent lamps were used as lighting sources. Each fluorescent lamps has different S/P ratio (scotopic lumince / photopic luminance). One experimental chamber was lit by daylight fluorescent lamps and the other chamber was lit by one of the other five fluorescent lamps. After the subjects judged the brighter room, they were requested to adjust luminace level in one chamber to get equal brightness with the other. Ratios of luminance by the compared lamp to that by the daylight lamp were calculated. The following results were obtained: the subjects judge of that the fluorescent lamp with high S/P ratio is brighter than the fluorescent lamp with low S/P ratio. The differences of brightness perception between daylight flourescent lamp and the other lamps decreases with a rise in luminance level. It became clear with regression analysis that not only photopic luminance but also scotopic luminace contributes to perceped brightness in according to luminace levels. Both of scotopic and photopic luminance is required to account perceived brightness in interiors.
