The spectral power distribution of clear sky light varies mainly from the following factors: density of aerosol, solar altitude and angular distance from the sun, and reflected light from ground surface. This paper investigates these factors and effects about variation of clear sky light. The spectral power distributions of clear skies are not measured but calculated theoretically. The following is found out: (1) The chromaticities of daylight in high latitudes are distributed up to the higher range of correlated color temperature (CCT) than in low latitudes and many chromaticities of daylight in low latitudes are distributed at the low range of CCT compared with in high latitudes. (2) The chromaticities of north sky light in low latitudes are distributed slightly to green side at high CCT and a little to purple side at low CCT compared with the chromaticities of north sky light in high latitudes. (3) The difference between the distributions of chromaticities of daylight falling on a horizontal surface in high latitudes and is low latitudes is much smaller than the difference between distributions of chromaticities of north sky light in high latitudes and in low latitudes.
Thermal design is one of the most important issues in developing compact self-ballasted fluorescent lamps which are required to be in smaller size and with higher output. In this paper, a simulation model is proposed using thermal network equations. The thermal network equation are derived from the theoretical system consisting of thermal circuit which is analogous with an electric circuit. The coefficients of the thermal network equations can be obtained by a model experiment using a heater. The calculated temperatures are in good agreement with the measured temperatures. The thermal simulation is useful for designing compact self-ballasted fl uorescent lamps.
This paper describes the developmental process of new prismatic panel for lighting fixture which satisfys both high efficiency and diffusion ability. Concretely, the result of improved opal panel for high efficiency and diffusion ability, the theory of accomplishing high diffusion ability by prismatic panel, the process of selecting prismatic element the simulation of luminance of prismatic panel by inverse-ray tracing method and the specification of surface mounted flourescent lighting fixture applied this prismatic panel are reported. The prismatic element is lozenge-shaped, with a length of 5.0 mm, a width of 2.9 mm and a height of 2.2 mm. The light which goes to the prismatic element just under the lamp is totally reflected at the internal prismatic surface, consequently apparent luminance of lamp through the panel is reduced. While the light which goes to the prismatic element between lamps is refracted downward, so luminance of panel between lamps is increased. Applying this prismatic panel, very thin surface-mounted flourescent fixture has been developed.
Ozone production capacity of the low pressure mercury vapor quartz lamp was measured in order to design industrial equipments for photo oxidation processes. The lamp used in the experiments was made from conventional quartz tube. A main spectral line is 253.7 nm in cylinder shaped 8 W lamps. Supplying air into an annular space of a double pipe structure, author examined the relation betwwen the concentration of ozone produced and gas flow rate (0.025-10 l/min). In the measurement the exposing length of the lamp was changed (2.5-105 mm), keeping the width of the annular space constant. Here, author obtained the relative formula between supplied gas quantity and the concentration of ozone produced on the log-paper. The ozone concentration increased with gas flow rate in the low rate range. However, it became in inverse proportion in the range of high gas flow rate. That is, a reversing zone of concentration was found in the experiments.