Horizontal Illuminance Research Articles

Practical Integrated Lighting Design with Daylight (Part 2)

By using the cumulative occurrence rate curve of the horizontal plane illuminance E0 from an unobstructed hemisphere of sky, the rate of switch-off time duration can be estimated for a designated illuminance E, where switch on and offs occur too frequently. In practical integrated lighting design, however, the number of switch on and offs will have to be reduced. This is done by taking the designated illuminance width in stead of designated illuminance.Taking this into consideration, E0-cumulative occurrence rate and the number of switch on and offs are calculated once again from the original recorded data for each 10%, 20%and 30% illuminance width of designated E.Based on these results, a utilization technique for integrated lighting design is presented. For a typical office room, the lighting engineer can easily estimate the rate of switch-off time duration. This estimation is made using a chart which is a combination of E0-cumulative occurrence rate curves and daylight factor distribution curves in an office room.

Impression of brightness of objects and interiors

Values of scalar illuminance are included in the IES Code for Interior Lighting for certain areas. There is evidence that cylindrical illuminance might be a better correlate with the impression of the brightness of an interior. Experimental work is discussed and reported that suggests that the geometric mean of vertical and horizontal illuminance is also a significant parameter when comparing observers' impressions of the equivalent brightness of objects. Some of the experiments described show that hemispherical illuminance is a very good correlate to the impression of the brightness of objects where a single direction of view is considered.

Simple expressions for predicting energy savings from photo-electric control of lighting

The cost-effectiveness of different types of photo- electrically controlled lighting systems is being examined at the Building Research Establishment. Using published data on availability of daylight, equations are derived to predict the maximum possible savings in artificial lighting use that can be achieved using photo- electrically controlled dimming or on/off systems. The equations are applied to two deep-plan spaces and figures are given for the relative maximum savings in artificial lighting use of three control systems: on/off, dimming and mixed. The savings range from 20%, to over 40%, of the energy used for uncontrolled lighting, assuming that a horizontal illuminance of 500 lux is maintained throughout the spaces. The effects of real variations in artificial lighting use are discussed.

Lighting techniques and associated equipment for outdoor colour television with particular reference to football stadium lighting

The general requirements of visual performance and comfort in stadium floodlighting are outlined; the essential differences between the problems posed by colour television transmissions and black-and-white television are pointed out. Horizontal and vertical illuminances and uniformity are discussed, together with glare problems. Side-mounted and tower systems are considered with particular reference to colour television requirements. Design aspects of the lighting equipment are discussed in relation to the colour television camera equipment. The need for computer planning is mentioned.

The role of the level and diversity of horizontal illumination in an appraisal of a simple office task : Saunders, J. E.Lighting Research and Technology, 1969,1.1, 37–43

The role of the level and diversity of horizontal illumination in an appraisal of a simple office task : Saunders, J. E.Lighting Research and Technology, 1969,1.1, 37–43

The role of the level and diversity of horizontal illumination in an appraisal of a simple office task

Observers were asked to rate their preferences for the lighting of a simple office task under a range of illumination levels and diversities. It is concluded that an increase by a factor of 2 in the current IES minimum service value of illumination for offices (400 lux), would be appreciated by the majority of observers and that the recommendation of a minimum uniformity ratio of 0.7 in the total working area, or at least in each unit of this area when the office space is broken up in some manner, is applicable at both low and high levels of illumination. Results were also obtained which indicate that the experimental conditions were reasonably well related to more normal office situations.

Atmospheric Optical Measurements in Central Colorado in Connection with Long Range Oblique Photography

In September 1966, an AF C-130 aircraft, instrumented with Visibility Laboratory optical and meteorological sensors, was flown along a path of sight from a camera on Pikes Peak to a target array near Castle Rock, Colorado. The beam transmittance for the path of sight was 0.238, the universal contrast transmittance was 0.161, and the path luminance was 2062 cd m(-2). A second data gathering descent was made from 9800 m, over the target array toward the southeast to an altitude of 1700 m. Beam transmittance for vertical path of sight for total atmosphere was 0.686. Atmospheric optical data presented include additional beam transmittances, attenuation length, background luminance, equilibrium luminance, horizontal path function, illuminances, and terrain reflectance.

3116 晴天空の太陽近傍部による水平面照度について(環境工学)

3116 晴天空の太陽近傍部による水平面照度について(環境工学)

The Flow of Light into Buildings

A knowledge of angular relationships is essential for studying the view through a window and for calculating daylight factors. A perspective drawing contains information about the various angles subtended at a chosen viewpoint and lends itself to the study of natural lighting. The traditional method of specifying daylight in terms of a horizontal working plane can give a misleading impression of the lighting conditions, which depend largely on light reaching vertical surfaces. Similarly the advent of luminance desigm in artificial light ing has created the need for some three-dimensional concept to replace horizontal illumination as a criteriom of adequate lighting. Illumination can be analyzed in scalar and vectorial terms. The calculation of scalar and vector illumination is discussed. For natural lighting each can be determined from perspective drawings. For artificial lighting the scalar illumination can be calculated from British Zonal data which provides an index of adequacy for many lighting purposes. The vector illumination indicates the directional qualities of the lighting. The ratio of vector to scalar illumination may serve as an index of modelling. -- AATA

Shift of Illumination Point and Change of Horizontal Illumination with the Inclination of a Ughting Fixture

Shift of Illumination Point and Change of Horizontal Illumination with the Inclination of a Ughting Fixture

明るさの判定に及ぼす空間の影響

Lightness of rooms rated by visual sense is no doubt largely affected with the holizontal illumination and the mean brightness in the whole visual field. But besides, we had a prospect that it would be affected with the shapes of rooms too. In other words, the adequat value of illumination or the mean brightness might differ from each other according to the hight or the width or the width or the depth of each room. We took for samples 18 concourses of railway station in Tokyo and its neighbourhood, and measured the mean horizontal illumination and the mean brightness in the whole visual field by a person standing at the centre of its entrance, and at the same time we (nine persons) memorized the psychological value of ligthness of each room in 7 grades. The relation between that psychological value of lightness and the shapes of rooms, especially the depth of room, is seen at Fig.8〜13. It would be concluted certainly from the results that the paychological value of lightness decrease according to the depth of room. Besides, the adequate value of the mean horizontal illumination and the mean brightness in the whole visual field were also obtaind. Fig.6 and 7 show these value, which are about 330lx and 150ml (meter Lambert).

Accommodative tracking: A trial-and-error function

The directional tracking of the accommodative system of three subjects has been analysed by following associated accommodative-convergence movements. An attempt was made to eliminate extraneous clues such as apparent vertical and horizontal target movement, size change, blur asymmetry and illumination differences, and also the possibility of learning patterns of stimulus presentations. Spherical and chromatic aberrations of the eye were left intact and astigmatism was uncorrected. For one subject the initial direction of change in accommodation was in error about fifty per cent of the time. The gross clue of the blurred image on the retina was always sufficient stimulus to allow the system eventually to reach the correct final level of accommodation. Statistical verification of the randomness of these data led to the conclusion that it is possible for the accommodative system to operate on an even-error signal with spherical and chromatic aberration intact, with uncorrected astigmatism, and in the presence of normal noise oscillations of the lens. Two other subjects made one hundred per cent correct responses even under conditions where chromatic aberration was removed as a possible clue. It is felt that major clues as to the direction of target movement can result from less than absolutely perfect alignment of the target on the visual axis and from blur asymmetry.

THE SWIMMING PLANE OF THE CRUSTACTEAN MYSIDIUM GRACILE (DANA)

1. Mysidium gracile (Dana) tends to move within a plane, the swimming plane, which is oriented as nearly as possible perpendicular to the directions of light and gravity.2. Horizontal illumination induces an orientation conflict which is resolved by maintaining the swimming plane in a slanted position intermediate between those positions dictated by the two stimuli.3. The turning tendencies of the dorsal light reaction increase with increasing light intensities.4. There is evidence that gravity- and light-induced turning tendencies inhibit each other.

Research on the Measurements of the Solar Radiation and Illumination Intensities

Synopsis: In this paper the report was described, concerning the measurements of solar radiation intensity and daylight illumination intensity, studied during these several years.The direct solar radiation intensity, received on a surface normal to the solar rays, was recorded automatically by using of the special apparatus deviced by the auther, comprising of the Moll-type thermopile, clock device with equatorial mounting and recording millivoltmeter. It was recorded that, on clear days, the maximum value of normal direct solar radiation intensity is about 1000 Wattim2 during the whole year on the average.By making use of those values recorded during each season, the solar constant and atmospheric transmission coefficients were calculated and tabulated.Further it is reported the results of measurements of the normal and horizontal illumination intensitiesof the sun during daytime and also the horizontal illumination intensities at twilight.An outline of the newly deviced self-recording apparatus for measuring the distribution of illumination intensities or brightness of heaven hemisphere is described, and also discussed on the osine-law of barrier layer photo-cell which was used during the whole series of measurements.

Electrical installations in hospitals

The paper reviews the considerations which apply more particularly to hospitals than to other public buildings. For permanent work, paper-lead cable is recommended for the circuits to the fuse-boards and wiring in conduit for the subcircuits. Under-floor ducts are not recommended for hospital wiring. Suggestions are made regarding the selection of accessories and fittings. For general ward lighting a comparatively low value of horizontal illumination is recommended, with local lighting at the beds. Capacitance dimming is described. The use in the future of fluorescent lamps is discussed. The shadowless lamp for operating-table lighting is described. Precautions to be taken against explosions in operating theatres are referred to. Requirements for screening in connection with high-frequency (diathermy) apparatus necessitated by war conditions are reviewed, and the opinion is expressed that regulations for this will be continued after the war. The precautions necessary in the construction and use of apparatus for electric therapy are discussed. Developments in X-ray apparatus are mentioned, and questions of voltage-drop and shielding briefly discussed. On ultra-violet treatment, the opinion is expressed that the mercury lamp, possibly supplemented by ordinary tungsten-filament lamps, should eventually entirely displace the more expensive arc-lamp treatment, and that there is no need to aim at an artificial reproduction of sunlight. Other subjects which are dealt with briefly are infrared rays, cardiograph wiring, heating, ventilation of operating theatres, water supply pumps, cooking, refrigeration, lifts and signalling circuits.

9) 傾斜矩形光源に依る水平面照度の解法に就て

9) 傾斜矩形光源に依る水平面照度の解法に就て

Submarine Illumination in Photometric Units

The paper describes a method of obtaining underwater illumination in photometric units. The results are given as total horizontal illumination at different depths and as cell current extinction coefficients of two bands in the visible spectrum. The effect of temperature on the submerged photometer is indicated, and a mean temperature coefficient between 0°C and 17°C is calculated.

The Photometry of Solar Eclipse Phenomena

The Electrical Testing Laboratories of New York desiring to supplement the work in the photometry of eclipse phenomena which it had done through three expeditions at the time of the 1925 eclipse, designed apparatus and methods and sent an expedition to Lancaster, New Hampshire to observe the eclipse of August, 1932. In preparing for this expedition features connected with the photometry of eclipse phenomena were considered anew and are discussed. The use of the term “brightness” with reference to the solar corona is criticized as misleading and not in accordance with photometric usage. The quantity to be measured is the illumination produced by the corona. Discussion is made of erroneous and misleading values for corona illumination which have been published and which refer to illumination produced not by the corona alone but by the corona together with a large area of sky and which have no especial scientific significance. Specially designed photometers are described for measuring the coronal light, the horizontal illumination and sky brightness. These have filters to give a color match in the photometric field as closely as the color to be encountered can be predicted. They have easily manipulated neutral screens to cover the range of intensities. The coronal photometer has an optical system whereby the field included is accurately defined and a “homemade” heliostat to keep the sun in position. There is also a photoelectric photometer for corona measurement consisting of a vacuum photoelectric cell with colored filters correcting its response to the eye sensitivity curve. This acts through an amplifier with an FP-54 tube and is fitted with an optical system for delimiting the field. Special recording arrangements are described. Cloudiness at Lancaster prevented any measurements of the corona light to be obtained. It was found that the total illumination on a horizontal plane at the time of totality was 0.35 footcandle.

THE PHOTOTROPIC EXCITATION OF LIMAX

The photic orientation of Limax creeping geotropically upon a vertical plate is such that the phototropic vector determining the angular deflection beta from the vertical path is proportional to log I. This is proved by the fact that with horizontal illumination tan beta is directly proportional to log I; with non-horizontal light rays from a small source the ratio See PDF for Equation is directly proportional to log I (where A = the angle between light rays and the path of orientation), the vector diagram of the field of excitation being in this case not a right-angled triangle.

Experiments on the light and tactile reactions of a cave variety and an open water variety of an amphipod species

The amphipod, Eucrangonyx gracilis (Smith), occurs in the waters of many caves in southern Indiana and is very generally and abundantly distributed in small surface streams in the same region. The individuals occurring in caves almost without exception have very little or no body pigment though possessed of the normal pigment in the eyes. Those living in surface streams have the usual amount of pigment for a crustacean. In other structural characters the forms are apparently alike.In an attempt to determine whether there was a physiological difference between the two forms they were tested for light and tactile reactions. These amphipods are negative to all intensities of light to which they respond. Extended series of light experiments using horizontal illumination were conducted during which every effort was made to maintain as precise conditions as possible. The cave form was found to be somewhat less responsive to light than the form living outside caves, but this difference was not large and was dist...