bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoelectric Photometers: Their Properties, Use and Maintenance
Authors: Preston J. S.
Published: November 2015

This Paper examines the problems arising in the application of emission photocells and selenium rectifier photocells to photometry. It deals with the difficulties of securing a close approximation to a linear scale, and to the spectral sensitivity of the standard eye; and also with the life, stability, and fatigue of photocells, temperature coefficient, dark-current, non-uniformity over the area of the sensitive surface, stray radiation, and the use of photoelectric instruments for measuring fluctuating light sources. In the case of rectifier cells the questions of the response of the cell to oblique illumination and of the size of cell best suited to any given purpose are also discussed. A number of colour correction filters proposed for use with both types of photocell, are cited.

The principles and methods of use of standard types of photometer circuits are described and critically discussed. The circuits included are the direct-reading and the integrating circuits for emission cells, and the light-meter, Campbell-Freeth, and balanced-cell circuits for rectifier cells. As an example of a complete instrument a new portable emission-cell photometer is described in which the amplifier circuit, comprising two stages of D.C. amplification, includes an electrometer tetrode, and gives a current gain of 2.107 with stability adequate for measuring photocurrents down to 2.10−14 ampere to within ±5%.

The Paper is an attempt to collate the information necessary to give the user a clear understanding of the possibilities and limitations of photoelectric photometers, and of the precautions necessary to ensure results of the highest possible accuracy. Selection of this information is based on experience of the last ten years at the National Physical Laboratory. Little that is novel is described, except the circuit for use with the electrometer tetrode, and work, as yet incomplete, on the fatigue of rectifier cells under monochromatic light of different wavelengths.
‘Lighting the Homes of To-Morrow’
Authors: Carne J. B.
Published: November 2015

The paper deals with the lighting of the homes of the ‘million.’ Using published and new statistical data, the author deduces the pre-1939 average weekly expenditure on artificial light and the level and quality of the illumination prevailing in the homes of the lower income group in the U.K. Suggestions are made for improving the quality of the lighting without increased expenditure, with emphasis on the influence of decorations, and a plea for efficient units designed in accordance with well-defined principles.

The author accepts the I.E.S. Code values, and concludes that attainment of them necessitates at least twice the pre-1939 expenditure on gas or electricity, for lighting. He contends that the use of higher levels will result mainly from precept and example and availability of low running-cost sources; but that very considerable and immediate improvement in quality of illumination would result from preferential taxation of suggested “Utility” units of approved design, and sympathetic action in regard to decorations by architects and building authorities.
Bright Light Sources, Part II.—The Electric Discharge Lamp
Authors: Aldington J. N.
Published: November 2015

In contrast with Part I, of a paper entitled “Bright Light Sources,” read before this Society on November 14, 1944, in which incandescent tungsten filament projector lamps were discussed, the present paper deals specifically with high brightness electric discharge lamps. Attention is directed to considerations of those factors wihich influence the brightness of the electric discharge and reference ismade to certain definte types of lamp which have emerged in the last few years, as well as to a number of types which are still in the experimental stage. To enable the discharge of an electric current to produce a light source of high brightness some or all of the following conditions must obtain in the arc: (a) High luminous efficiency; (b) high voltage gradients; (c) high current density. The inter-relation of these three factors is discussed. Both air-cooled and water-cooled mercury vapour lamps are described and some details are given of their properties and uses. Attention is drawn particularly to the 500 and 1000-watt ME air-cooled compact source mercury vapour lamps. Progress in the development of ME-type lamps up to about 15 kws. is outlined, and some of the factors which governed various stages in the development are described. The second section of the paper deals with low-pressure gas discharge lamps. The essential circuit components for operating high brightness condenser flash lamps of this type are described. The magnitude of the discharge currents and lumen outputs which can be obtained are indicated. Some applications of condenser flash discharge lamps are mentioned.
The Brightness and Legibility at Night of Road Traffic Signs
Authors: Smyth J. S.
Published: November 2015

An investigation to determine the most satisfactory brightness of lettered signs seen against different background brightness levels is described. “Ideal” sign brightnesses are suggested, lying between the minimum for threshold legibility and the maximum acceptable without ill effects from glare. The ideal brightness for legibility was found to be unaffected by the colour of the sign, and was the same for black on white or white on black signs. The effect of disturbing factors such as glare from automobile headlights, and dirt collection on the sign are considered; such handicaps do not affect legibility distance very greatly, tout may seriously reduce the conspicuity of the sign.

The second part of the paper gives an account of a study of reflex reflecting lensed symbols used on traffic signs: methods of fitting lenses, and small modifications to some symbols are suggested to make recognition easier.

The work described was carried out by a technical committee, called toy the Illuminating Engineering Society at the request of the Ministry of Transport. The results have led to some recommendations made in the Departmental Report on Traffic Signs, 1944.
Decoration and Industrial Lighting
Authors: Nelson J. H.
Published: November 2015

The purpose of industrial lighting and decoration is to provide conditions in which an operator can see to work and has the will to work. The fundamental researches on vision directly indicating the type of conditions desirable for good seeing are described and summarised in the form of a set of ideal seeing conditions. Not the least important of these conditions is the provision of agreeable surroundings by the choice of suitable decoration and lighting. Recent researches in colour harmony are described and, although, so far, experiments have been confined to a very restricted set of conditions, this work is used to draw up a series of practical recommendations on industrial decoration.

Since the type of decoration scheme suggested is quite different from that found in the majority of factories, details are given of two schemes which have been found successful. These schemes are illustrated by photographs and the practical experience gained since their installation over three years ago is described.
The Application of Modern Flash Discharge Tubes
Authors: Bicknell C. R.
Published: November 2015

A flash discharge tube is a light source that is designed to be operated by a condenser discharge, and thus to produce flashes of very high intensity and very short duration. It may be operated in conditions in which these flashes are isolated from one another by relatively long periods of time, or in which they follow one another in rapid succession.

The high current density conditions of operation result in the production of light of excellent spectral quality, whilst the flash duration is so short as to be capable of arresting very high speed motion. It is not practicable, within the compass of a paper such as this, to refer to all the manifold purposes to which flash discharge tubes can be usefully applied.

It has, therefore, been the author's endeavour to discuss flash tube applications on broad rather than specific lines and to cite particular applications as examples of general practice.
Acrylic Plastics in Lighting
Authors: Harper W. E. , Walker H. P.
Published: November 2015

Acrylic plastics are among the most important of the new materials being used by lighting engineers in the construction of fittings.

Available in many varieties, their optical, thermal, and mechanical properties are reviewed and related to the use of the material in lighting equipment.

Fabrication methods for moulding and shaping the material must be adapted to its characteristics, and details are given of the more widely used techniques, including shaping, high pressure moulding, machining, and jointing.

The developing use of the material in selected fields of lighting practice is outlined, and fittings typical of modern practice described.
The Gas Arc
Authors: Aldington J. N.
Published: November 2015

The term “Gas Arc” has been applied to a recently developed range of xenon-filled discharge tubes operated under conditions which cause them to emit radiation of sunlight quality. The radiation from the Gas Arc is characterised by an intense continuum extending from the ultra violet through the visible region into the infra red.

An introductory section is followed by some considerations of the factors which influenced the development of this new source. The luminous and other characteristics of the Gas Arc in its present form are given, and it is shown that a 5-kw, xenon-filled lamp has an initial efficiency of 25–30 l./w.

The simple circuit arrangement necessary for the ignition and operation of Gas Arc lamps is described.

The concluding sections deal with some of the latest developments in this field and with an examination of possible applications.
The Lighting of Churches
Authors: Rettig L. C.
Published: November 2015

This paper discusses the illuminating engineering principles applicable to the lighting of churches. The requirements of various denominations are discussed in conjunction with different styles and periods of architecture. Illumination methods and associated fittings are classified and their suitability and limitations for a number of situations are indicated. Notes are included on historical aspects, light sources, installation, and new projects.
Acrylic Enclosures for Flameproof Lighting Equipment
Authors: Collins P. H. , Harper W. E.
Published: November 2015

Many of the flameproof lighting fittings used in the large-scale coal-face lighting trials have enclosures made of the acrylic plastic polymethyl methacrylate.

This new material has characteristics which are very different from those of the toughened glasses more generally used in flameproof equipment, and it has been necessary to evaluate its relevant properties.

The research work described in this paper covers investigations of mechanical, thermal, optical and physical properties of methacrylate, and the effect of various factors on these properties.

Performance data have been obtained which should enable the drafting to commence of a new British Standard Specification governing the design of methacrylate enclosures for flameproof lighting fittings.
Lighting of Fibre and Fabric
Authors: Hewitt H.
Published: November 2015

The paper reviews the applications of artificial lighting at all stages in the manufacture of clothing, from the raw fibre to the fabric, and from the fabric to the finished garment.

Industrial lighting requirements are briefly assessed; observations are made upon interesting developments in this field and upon possible future trends.

More detailed reference is made to the applications of light sources for quality control, particularly in regard to colour matching and light-fastness testing.

The role of the newer illuminants in display lighting is discussed from the viewpoint of both vendor and purchaser, and a new approach is suggested to the problem of apparent colour-change.
Measurement, Representation and Specification of Colour and Colour Rendering Properties of Light Sources
Authors: Winch G. T. , Ruff H. R.
Published: November 2015

The problem is stated and is followed by a description of methods of measuring and specifying colour and colour rendering properties, with particular reference to tubular fluorescent lamps.

It has been found desirable in Great Britain to specify the colour characteristics of these light sources in terms of both their colour rendering properties expressed as percentage luminance in eight spectral bands, and their colour appearance in C.I.E. chromaticity co-ordinate limits. Typical forms of colour and spectral band specification are indicated, and a preferred form of block diagram is shown in which the percentage luminance values in the eight spectral bands are plotted on logarithmic ordinates.

New and more accurate measuring apparatus is described, to enable lumens, trichromatic co-ordinates and luminance in eight spectral bands to be measured directly on the C.I.E. system in quick succession in the one apparatus. The accuracy of such precision instruments may make it possible ultimately to specify colour rendering properties in terms of percentage luminance in spectral bands alone.
The Properties of White Rigid Polyvinyl Chloride Sheet
Authors: Harper W. E.
Published: November 2015

An opaque white grade of rigid polyvinyl chloride sheet has been developed* for use as a diffusely reflecting material and this paper reports the results of photometric, thermal, mechanical and ageing tests made on production sheet. The tests show rigid p.v.c. to have the properties required of a highly efficient reflecting material; the thermal characteristics, however, limit use to fittings in which the temperature of the shapings is not greater than 55 deg. C.
The Colour-Rendering Properties of Fluorescent Lamps and a Proposed New Method of Specification
Authors: Henderson S. T. , Waigh D. T.
Published: November 2015

To express the colour-rendering properties of light sources, a band system of presenting the spectral energy distribution has been used. The best known example of this is Bouma's eight-band system. In this paper Bouma's method of treating the problem is criticised, and the uses and drawbacks of band systems discussed. The next stage of condensation of information on spectral energy distribution leads to single figures of merit to measure colour-rendering properties. Related to this is the present proposal for expressing a single feature of colour-rendering behaviour of fluorescent lamps, namely the red-rendering efficiency, as an index which will distinguish easily between lamps of the “high efficiency” and “high fidelity” types. It is based on the ratio of energy output at two selected wave-lengths, compared with the ratio for a black body or “Planckian radiator” of near or identical colour appearance. Various methods of determining the index are discussed, varying from a calculation based on spectrophotometry to a direct meter measurement. Data are given for a wide selection of lamps.
Application of Fluorescent Dimming Circuits
Authors: Ballin H. H. , Vine W. J.
Published: November 2015

The paper surveys the use of fluorescent dimming for different lighting applications. New requirements have led to the development of new circuits which are briefly discussed. A short description of the lighting equipment is followed by a consideration of some uses of dimming in industrial lighting. The potentialities of fluorescent stage lighting are discussed in the light of experience. Other applications considered include colour changing floodlighting of buildings, outdoor illuminations and display lighting. It is concluded that fluorescent dimming has made possible new and artistic lighting effects.
Studies in Interior Lighting
Authors: Waldram J. M.
Published: November 2015

The mechanism of interior lighting has been recently discussed in a Report of a Committee of the National Illumination Committee. The present paper records studies on three aspects of interior lighting: Adaptation, Revealing of Form and Texture, and Emphasis. It is proposed that effects of Adaptation should be taken into account in lighting calculations and values of Apparent Brightness used, for it is shown that figures of apparent brightness accord much better with experience than figures of absolute luminance, and explain anomalies which are found with absolute figures.

A new method of calculation is outlined, whereby the effects of inter-reflection can be found very simply without complex theory and by means suitable for day-to-day work, so that the installation can be designed from a specification of apparent brightness distribution.

The mechanism of the revealing of form and texture is discussed. Apparatus for the quantitative and systematic study of modelling and shadow are described; modelling indices and methods of portraying modelling capability of the lighting are proposed. Results in interiors of different types are given.

Emphasis is a more subtle effect than modelling and does not lend itself so well to quantitative study; it is discussed qualitatively and more briefly.

The techniques of experimental study of complete interiors are described and further general observations recorded. The effects of the factors discussed upon the lighting design for interiors are considered and possible techniques outlined. An appendix gives definitions of special terms used in the paper; a second appendix discusses techniques used, and a third describes the new method of calculation.
Two Supplementary Studies on Glare
Authors: Hopkinson R. G. , Petherbridge P.
Published: November 2015

An investigation has been made to see if assessments of glare discomfort in model-scale lighting installations are significantly different from assessments made in full-scale installations.

A further study has been made to see how far the general population differs in its assessments of glare discomfort from observers experienced in subjective judgments.

The results show that the experimental data and empirical formulae derived from model-scale studies on glare can be applied with confidence to the design of full-scale lighting installations, and that the glare conditions derived directly from these formulae will satisfy about 85 per cent. of the general population.
Preliminary Survey of Colour Preferences in Television Pictures
Authors: Gilbert M.
Published: November 2015

This paper describes an investigation carried out in order to determine some of the colour-rendering characteristics that a viewer of colour television would consider to be satisfactory. It is concluded that the colours of a reproduced scene need to be less saturated than the colours of the original scene being televised. This is in line with findings on colour film reproductions. There is evidence to show that it may also be desirable to make the reproduced colours rather more blue than those of the original scene. Although it is important that the home viewer should not have to deal with too many controls, it is suggested that a knob to adjust the red-green ratio of a colour picture may be desirable.
The Seasoning of Tungsten Filament Incandescent Lamps for Use as Photometric Standards
Authors: Blevin W. R. , Brown W. J. , Sarma K. S.
Published: November 2015

The rate of seasoning of gas-filled and vacuum tungsten lamps is consistent with the view that recrystallisation of the tungsten filament is the main process involved. The changes during seasoning indicate a decrease in emissivity of the filament which is largely non-selective with regard to wave-length. Seasoning at a relatively low colour temperature almost completely stabilises standard lamps for operation at higher temperatures, and has the advantages of producing less blackening on the envelope and expending less of the useful life of the lamp.
A Preliminary Study of Reflected Glare
Authors: Petherbridge P. , Hopkinson R. G.
Published: November 2015

Bright light sources, reflected in glossy or semi-matt surfaces, can cause glare which may give rise to serious complaints. The best palliative is naturally to avoid the use of specularly reflecting surfaces, but in many situations this is quite impossible.

A study has therefore been initiated of the factors which give rise to reflected glare. This study, although in the preliminary stages, has already demonstrated the important fact that the chief manifestation of reflected glare is the distraction caused, rather than discomfort or disability.
Decorative Lighting—A Designer's Approach
Authors: Durrant D. W.
Published: November 2015

This paper takes for granted that the technicalities of lighting are well known and therefore deals broadly with the aesthetic aspect. From the assumption that lighting is an integral part of interior-decoration, it examines the approach of a designer when dealing with a known interior, and compares this with the problem of designing fittings for a catalogue. It discusses the inveterate question of what is good design, and a definition is suggested.

In reviewing the trend of design, it refers to colour, form, light and shade, contrast and novelty, and considers the factors which influence changes in fashion, taste and technique. It includes an appraisal of some installations in relation to contemporary thought, and concludes with a plea for more good design and “lighting artists” in the industry.
Automobile Headlamps
Authors: Nelson J. H.
Published: November 2015

The specification of the headlamp meeting beam has been a matter of disagreement between lighting engineers, in Europe on the one hand, and in the United Kingdom and the United States on the other, for many years.

Although the setting up of a Joint Working Party to study the question by the International Standards Organisation (I.S.O.) and International Commission on Illumination (C.I.E.) has not resolved these differences, the report(I) submitted by the Working Party to the C.I.E. in Zurich in 1955, and to the I.S.O. in London in 1956, records, for the first time, an attempt by each side to understand the ideas and problems of the other, and registers complete unanimity on the overwhelming importance of the correct use and maintenance of car headlamps.

The purpose of this paper is to describe the background against which these tests were carried out, and the nature of the results. The Working Party's recommendations are discussed and the adoption of an asymmetric beam, hitherto the distinguishing characteristic of Anglo-American practice, as the new unified European beam is noted.
Ambient Temperature Effects in the Photometry of Fluorescent Lamps
Authors: Blevin W. R.
Published: November 2015

The dependence of the luminous and electrical characteristics of fluorescent lamps on the ambient temperature introduces complications in the photometry of these lamps. It is shown that if both the luminous flux and the electrical characteristics of a stable lamp are measured over a range of ambient temperatures, then on future occasions of burning within that range it is possible to deduce the luminous flux of the lamp from measurements of its electrical characteristics without requiring a knowledge of lamp or ambient air temperature.
Characteristics and Applications of Photo-Electric Cells
Authors: Benson F. A.
Published: November 2015

The paper deals first with the theory of photo-emission and the properties of photo-emissive cells. The various types of cathode which have been developed are described. Information is then presented on gas-filled cells and photo-electric multipliers. Mention is made of colour response, fatigue effects, dark current, noise, frequency response and associated circuits. The mechanisms and characteristics of various types of photo-voltaic and photo-conductive cells are then discussed, and some details of semi-conductor photocells are included. The applications of photocells to photometry, spectrophotometry, astronomy, radiation detection, recording of transient optical phenomena and in reflectometers, fluorometers, refractometers, colorimeters and turbidimeters are briefly discussed. Some infra-red photo-electric equipment is mentioned and finally a large number of miscellaneous photocell applications are listed.
Lighting at the Brussels 1958 Exhibition
Authors: Boereboom Andre
Published: November 2015

The lighting of an exhibition such as the Brussels 1958 Exhibition is a considerable undertaking. This paper gives a general outline of the problems of electricity supply and gives some details of the lighting of outside areas, the interiors of a few of the many pavilions and of the various water features and fountains.
Practical Application of Direct Discomfort Glare Research in the New Australian Artificial Lighting Code
Authors: Lowson J. C.
Published: November 2015

Practical lighting design has hitherto been seriously handicapped by the meagre amount of quantitative data on discomfort glare in most current lighting codes and handbooks. Much valuable fundamental information about glare is available, but before this knowledge can be transferred from the laboratory notebook to the lighting design handbook it must be converted into a form simple enough for the practising lighting engineer to use at the drawingboard stage of design, and it is with the solution of this and related problems that the present paper is primarily concerned. It is shown that by taking a realistic view of the accuracy required when specifying permissible luminance limits for general lighting luminaires, it is possible to devise a tabular method of specifying such limits which is exceedingly quick and simple to apply, yet subtle enough to take reasonable account of the known facts about glare. This new table of recommended luminance limits (for diffusing luminaires and bare fluorescent lamps used for evenly distributed general lighting in work places) has been incorporated in the new artificial lighting code (A.S. No. CA.30) recently published by the Standards Association of Australia.
Some Recent Developments in Light Control
Authors: Stevens R. W.
Published: November 2015

After a brief consideration of the fundamental principles involved, a number of recent developments in the techniques of light control are reviewed. Particular reference is made to the application of injection moulding techniques to the manufacture of prismatic assemblies and the use of new aluminium alloys and finishing methods in the construction of specular reflectors. A method of distributed light control is also described, whereby a number of spaced locations may be lit by a single remote source.
Progress in Electric Lamps
Authors: Jenkins H. G.
Published: November 2015

During the past twenty-five years there has been spectacular progress in the development of electric lamps. While this applies mainly to discharge sources, much work has gone into incandescent lamps, which, despite their relatively low luminous efficiency, have not diminished in importance. An entirely new method of converting electrical energy into light by electroluminescence has been evolved, which, however, has not fulfilled its early promise. On the other hand, at a time when progress in conventional discharge sources might reasonably be expected to have levelled off, new ideas have evolved and substantial improvements have been made. The paper discusses the more important developments and trends in the field of electric lamps.
Retinal Illumination and Age
Authors: Weale R. A.
Published: November 2015

As our eyes age the amount of light reaching the retina decreases. This is attributable largely to changes in the pupil diameter, to the yellowing of the lens and, to a smaller extent, to a change in the effective path-length of light through the lens. The age variation of retinal illumination is estimated on the basis of published data for standard illuminants A and C, and for three types of fluorescent lamp. In all five cases the small difference found to exist between the light-adapted and dark-adapted eye is greater than differences between the lamps considered. In general, retinal illumination at the age of 60 is about one-third of the value corresponding to an age of 20. The practical significance of the estimate is discussed.
Lighting for Inspection
Authors: Bellchambers H. E. , Phillipson S. M.
Published: November 2015

Lighting plays a major part in the efficient performance of industrial product inspection, and this paper describes the various ways in which light can be used most effectively for this purpose. The visual inspection problem is analysed and shown to involve design for the whole of the visual field. The value of natural and artificial light in revealing faults is discussed; general and local lighting problems are considered and various types of inspection booth are described. Under the heading of Inspection Lighting Techniques the ways in which diffuse lighting and directional lighting may be used are given, together with data on suitable light sources. 'Assisted Vision' using magnification and projection is described; whilst a section on 'Extended Vision' examines the use of colour, monochromatic and polarised light, UV radiation, photography and stroboscope devices.
Practical Photometry of Lighting Fittings
Authors: Wilman D.
Published: November 2015

The present interest in photometric data has led to a re-examination of the degree of accuracy and reproducibility reasonably attainable in the photometry of lighting fittings. Practical difficulties limit the degree of accuracy obtainable; care must be exercised in the planning and execution of a test for the data obtained to be of real value.

This paper reviews the type of data required, and the basic test equipment necessary. The design of typical test procedures is discussed, with particular attention to details which contribute substantially to consistency and accuracy of results. Special requirements associated with certain discharge lamps are included, and some time-saving aids are described.
Colour-Rendering Tolerances and the Colour-Rendering Properties of Light Sources
Authors: Crawford B. H.
Published: November 2015

Good colour-rendering is defined relative to total radiator standards, and the problem of the determination of practical tolerances is outlined. Experiments are described from which a series of six spectral bands was derived, which could be used to determine colour-rendering tolerances and to classify the colour-rendering properties of a light source; the effect of variation of the luminance (relative to the reference source) of these bands, individually or in combination, was studied in detail, and a system of tolerances developed which can be used to indicate detailed spectral (band) variation or to give a single figure of merit (or classification) for the colour-rendering quality of a light source. The system has been tested by some large-scale trials on colour-rendering acceptability, and is applied to give a broad classification of normal types of British tubular fluorescent lamps. A comparison is made briefly of assessment on this basis with others that have been proposed.
Practical Problems of Specifying and Measuring Colour-Rendering Properties
Authors: Winch G. T.
Published: November 2015

The visual sensations involved in the perception of colour-rendering cannot be measured directly, but subjective experience shows some correlation, over limited ranges, with the spectral energy distribution (spectral radiant power) of the light incident on the surfaces and objects illuminated, when they are viewed under strictly defined conditions. The practical problems which arise in attempts to specify and measure these objective characteristics of the stimulus which are related to colour-rendering, are reviewed and appraised; in particular, attention is drawn to the difficulties of accurate spectro-radiometry, the maintenance of light standards, and the complex nature of the colour shift method now preferred by the USA and Germany.

Suggestions are made bearing on the possible proposals to the CIE in 1963 concerning revision of the CIE 1948 provisional recommendations in relation to the measurement and specification of colour-rendering. An interim modified spectral band system is suggested, which would include the ultra-violet region of the spectrum because of its importance in relation to the colour appearance of objects and materials which are fluorescent; colour-rendering in the objective sense would be specified in terms of chromaticity and relative luminance (as in the CIE 1948 system) in the visible bands, with an appropriate weighting factor for the ultra-violet radiation. Tolerances would be based on the Crawford system which takes account of the effects in contiguous bands.

Because of the importance of chromaticity and spectral energy distribution measurements in relation to colour and colour-rendering, reference is made to the accuracy currently achieved, both in the standardising laboratory and when using commercial apparatus and techniques at present available to industry. Possible future developments are also indicated.
Artificial Lighting in Hospital Wards
Authors: Cross B. H. , Lyons S. L.
Published: November 2015

The paper examines the problems relating to artificial lighting in hospital wards, and offers some rational solutions in terms of lighting fittings design. It also shows application techniques to produce adequate illumination with minimum glare. Wards of traditional and modern layout are discussed, and the principles of lighting them are examined in relation to the recumbent patient as well as the needs of the staff; the study includes general lighting, bed-head lighting, night-lighting, watch-lighting and lighting for examination.

The technical requirements for ward lighting fittings are considered; as well as having the necessary light distribution and brightnesses, the fittings must be hygienic, safe both electrically and mechanically, silent in operation and easy to maintain. These requirements are achieved in some practical lighting fittings which are described, some of which incorporate unique though simple optical designs. Reference is made to economics and the choice of light sources for ward use.

The paper includes a section on the lighting of corridors and shows a possible new method.
Measurement of Impurities in Lamp Filling Gases
Authors: Allwood W. N.
Published: November 2015

Some modern techniques for measuring the main impurities (water vapour, oxygen and carbon compounds) in the gas filling of tungsten filament lamps are briefly indicated, and sampling techniques for maintaining good control of the purity in lamp manufacture are outlined.
High Pressure Rare Gas Filling for Tungsten Filament Lamps
Authors: Moys B. A.
Published: November 2015

An expression is derived for the theoretical life of a tungsten filament lamp when failure is due to internal transport of tungsten. The predicted dependence of life on the nature and pressure of the gas filling is tested against experimental values reported by Schilling.
Lamp Vibration
Authors: Coaton J. R.
Published: November 2015

Numerous arbitrary test devices have been introduced which bump or vibrate a lamp to try to select suitable lamps for environments where shock and vibration are present; these devices in general are unsatisfactory. Failure due to vibration is usually caused by a component in the lamp being in resonance with a vibration frequency generated in the environment, which causes large magnifications of movement. A method of vibration testing and of presentation of results has been devised which enables the ‘vibration characteristics' of a lamp to be determined; with a knowledge of the frequency and severity of vibration encountered in its normal use, these two pieces of information can be integrated to give a formula for the ideal lamp. It is usually impractical to have the ideal design for any one service, but useful compromise designs can be made.

The lamp fitting can influence the severity and range of frequencies transmitted to the lamp, with useful or disasterous effects if a dangerous range of frequencies is attenuated or amplified; thus proper design of the fitting can make a valuable contribution to improving the life of lamps in rough-service applications. The complete solution is not just a stronger lamp; realistic test procedures, determination of exactly what a lamp must withstand, and the scientific design of both lamp and fitting are some of the aspects to be considered.
Hospital Lighting: Official Recommendations and Recent Installations in Britain
Authors: Petty D. J.
Published: November 2015

The hospital building programme is reviewed, and the requirements of modern ward lighting are considered in relation to the recommendations drawn up by the DSIR Joint Committee on Lighting and Vision and commended to Hospital Boards by the Ministry of Health.
Hospital Lighting: Developments in Sweden
Authors: Pütsep Ervin P.
Published: November 2015

Light is of great psycho-physiological importance for human welfare: glare, however, can have a most deleterious effect, and especially so in ill-health. The lighting of hospital wards is discussed: the needs both of patients and of hospital staff are considered, and reasons are suggested for the failure of present-day equipment to meet these needs. A description is given of studies of ward lighting which have been made by the Central Board for Planning and Equipment in Stockholm: their recommendations for illumination levels are quoted, with a brief comparison of values from other Continental countries.
Glass for Modern Electric Lamps
Authors: Hawkins F. S.
Published: November 2015

Glass for electric lamps must have many different properties, e.g. transparency, resistance to heat, ability to form hermetic seals with the current leads, resistance to chemical attack and weathering, and different types of lamps require glasses differing in composition. Appropriate methods of glass melting are described in this paper, and the necessary properties of glass for tungsten lamp bulbs, fluorescent tubes, pinches and for sealed beam headlamps are discussed; appropriate compositions and forming methods are also given. Production methods for glass and quartz tubes for high pressure discharge lamps are outlined and the particular problems of sodium lamps—glass blackening and argon absorption—are discussed in detail.
Specifications for Lighting Equipment—Their Purpose and Preparation
Authors: Wilman D.
Published: November 2015

The importance of standard specifications in the lighting industry is increasing rapidly but their efficient use can only be ensured when the manufacturer, consultant and user know something of the foundations upon which such specifications are built. The process of producing a British Standard Specification is described, explanatory examples of some of the technical problems being drawn from the newly published B.S. specification for lighting fittings. Reference to the work of, and inter-relationship between, international standardisation bodies is included together with some ancillary subjects closely related to the use of standard specifications by purchaser and manufacturer.
Lighting and the Environment
Authors: Hewitt H. , Bridgers D. J. , Simons R. H.
Published: November 2015

The whole subject of quality in lighting is recognised as a complex of inter-related elements. The limited purpose of the paper is to take up a few loose ends in a tangled skein, to attempt some tentative methods of study, and to make suggestions for further work.

There is little difficulty in identifying those qualitative elements in the lighted interior which contribute to the total visual experience. The paper attempts to show the relative influence of those elements, and to investigate two of them in some detail. The paper also reports on a programme of comprehensive appraisals of lighted interiors, and discusses the difficulties inherent in the organisation of subjective assessments, the choice of observers, and the interpretation of the results.

The two elements chosen for special study are modelling and the brightness pattern. Results are given of a subjective investigation into the acceptability of various degrees of modelling produced by different lighting arrangements and decorative schemes in a small office. Alternative methods of measuring modelling effects are discussed and attempts are made to relate these measurements to subjective judgments. A simple study of the comparative acceptability of brightness patterns has been carried out by means of an adaptable lighting system and the results of numerous subjective assessments are discussed. Much more experience of such critical studies will be required in order to guide the specification of brightness ratios. At that stage luminance design methods will be required, and the paper includes a practical example of one design method worked out in detail.
Plastics in the Lighting Industry
Authors: Brain S. H.
Published: November 2015

The paper deals with the use of plastics materials based chiefly on polymethylmethacrylate and polystyrene for transparent and translucent lighting enclosures. The development is briefly traced from the first introduction of shaped acrylic sheet for fluorescent reflectors and diffusers to the highly complicated range of light controlling enclosures in production today. The manipulation of acrylic sheet is described comparing the old blowing techniques to the present method of producing modern re-entrant and deep drawn shapings. The introduction of modified polystyrene and its effect on the market due to new manufacturing methods is discussed. Extrusion by ring and profile dies and methods of post-extrusion treatment of both sections and sheet to give prismatic patterns are described, and injection moulding practice is discussed together with the possibilities of the production of large area moulding by this method. Some speculation is made on future plastics developments affecting the lighting industry.
Glare as a Criterion for Quality in Street Lighting
Authors: de Boer J. B. , Schreuder D. A.
Published: November 2015

A simple method is given for determining the degree of discomfort glare in street-lighting installations. This method is derived from results obtained partly from new investigations and partly from previous tests. Results arrived at by this method are compared with the glare produced in existing lighting installations. A comparison is also made with the rules laid down in the recommendations for public lighting published by the CIE and in the BSI code. It is suggested that standards for the limitation of glare, for use in street-lighting codes, can be determined on the basis of this method.
The Electrical Control of Lamp Light Output
Authors: Lark G. T. K. , Stevens W. R.
Published: November 2015

The basis of all electrical dimming systems is that the light output of an electric lamp varies with the current passing through it. Three methods may be recognised, namely, resistive, inductive and electronic; all are applicable, singly or in combination, to both incandescent and discharge lamps.

For theatrical work using incandescent lamps, the thyristor permits dimming systems with highly organised control arrangements. The greater difficulties inherent in discharge lamps can also be overcome, so that fluorescent tubes, in particular, can be controlled with precision.

Inexpensive automatic control of interior lighting linked to daylight offers intriguing uses particularly as applied to permanent supplementary artificial lighting.
Inter-Relationship of the Design Criteria for Lighting Installations
Authors: Jay P. A.
Published: November 2015

The various design criteria which have from time to time been proposed for lighting installations in working environments are examined. It is shown that there is a limited range of conditions within which it is possible to satisfy them all with the exception of direction of modelling, while some daylight from side windows will be sufficient to correct the direction of modelling during a large part of the year. The range of conditions to satisfy all design criteria simultaneously may conveniently be expressed as a set of illumination values for the walls and ceiling in terms of that of the working plane, taken together with the requirement for some daylight from side windows and reasonably high reflectances of internal surfaces.
Reflex Interactions during Whole Head-and-Body Tilts are Modified by Age in Humans
Authors: Paquet Nicole , Hui-Chan Christina W.Y.
Published: November 2015

We have demonstrated that lower limb extensor muscle response to tibial nerve stimulation is significantly facilitated by whole head-and-body tilt in the forward direction. Our aim was to examine whether this reflex interaction is influenced by age. Reflexes were elicited in lower limb muscles by electrical stimulation (ES) of the right tibial nerve. We compared reflexes during supported stance (ESalone) and sudden forward tilting of the whole head-and-body (Tilt+ES) between 10 healthy subjects aged 66 ± 4 years and 13 subjects aged 27 ± 3 years. In young subjects the area of response evoked in the ipsilateral vastus lateralis (iVL) was significantly increased by 74% during Tilt+ES as compared with ESalone (p < 0.05). Moreover, the latency of contralateral VL and soleus muscle responses (cVL and/or cSO) was significantly shorter by 61 ms during Tilt+ES than ESalone (p < 0.01). In contrast, older subjects showed no significant increase in the excitability of iVL muscle response and cVL and/or cSO muscle responses during Tilt+ES as compared with ESalone despite the application of similar intensity of ES and head acceleration as in young subjects. Our findings showed that the interaction between ES-evoked and tilt-evoked responses in lower limb extensor muscles is modified with age, which suggests modifications of sensorimotor integration involved in balance control.
Pharmacologic Treatment of Cognitive Deficits and Hypersexuality Due to “Shaken-Baby Syndrome”
Authors: Schmidt John G. , Schneider William N.
Published: November 2015

Objective:

To describe the clinical effects of amantadine and propranolol in an agitated pediatric patient with cognitive deficits, hyperactivity, and hypersexualism secondary to “shaken-baby syndrome.”

Background:

Patients with shaken-baby syndrome can present with cognitive and behavioral impairments.

Case:

A 9-year-old girl presented with cognitive impairments secondary to shaken-baby syndrome at 3 weeks of age. She was receiving many medications, including dextroamphetamine, methylphenidate, and clonidine, that were not effective in improving her cognitive status or decreasing her hypersexuality. She was weaned from stimulants and clonidine and prescribed amantadine 100 mg bid with improvement of attention, concentration, and cognition, although hypersexuality remained. She was then started on propranolol 10 mg tid and a gradual increase to 40 mg tid with amelioration of hypersexuality and hyperactivity and no unwanted effects noted. Self-weaning of propranolol was associated with the return of hypersexuality. The combination of amantadine and propranolol led to improvement of cognition and behavior, especially intellectual functioning and appropriate socialization with peers, respectively.

Conclusion:

Cognitive deficits and hypersexuality with hyperactive features due to shaken-baby syndrome may respond to the drug regimen of amantadine and propranolol.