The Design and Performance of Industrial Lighting

The paper is divided into two parts.

PART I deals with the design of lighting equipment and ancillary apparatus from the points of view of maintenance, safety, performance and simplicity of manufacture. The author's statements are based upon the checking of large numbers of artificial lighting installations during recent years. It is held that the experience gained during the war period, when little change occurred in industrial lighting equipment, should influence designers in developments for the future.

Special reference is made to questions of earthing, electrical and mechanical safety and to the temperatures attained in lighting fittings, which latter it is claimed are frequently too hot for service with normal cables.

Effects of corrosion and the specification of the quality of vitreous enamel are discussed.

Suggestions are made for the extension of Standard specifications to ensure inter-changeability in preference to the present tendency to limit their scope to performance requirements—including references to lampholders, low voltage lighting equipment and local lighting reflectors.

Photometrical evidence is offered in a novel form of diagram of the similarity in the light distributions from vitreous enamelled reflectors of different shapes with recommendations for a standardised design in place of the present alleged unnecessary multiplicity of patterns.

The electrical tracking effects of dust and the problem of dustproof lighting fittings are discussed. Particulars of a range of special totally-enclosed reflectors developed for war factories are given.

PART II draws attention to certain aspects of present-day practice in the design of industrial lighting layouts and suggests a greater degree of earlier co-operation between the factory owner and the illuminating engineer, with a fuller definition of the responsibilities of the latter.

Some special installations are discussed and comments made on the existing codes of illumination practice and the effects of decorations.

Special reference is made to lighting of hot-working areas in steel works, and the author's contention that reasonable illumination does not interfere with normal working conditions is upheld by certain quantitative experiments.

The experiments described also indicate that incandescent metal tends to reflect a greater proportion of incident light with increases in temperature and under certain circumstances may actually appear hotter under augmented illumination. This is the reverse to opinions frequently stated.

Comments on experience in connection with maintenance are given with recommendations for an ordered scheme for carrying out such work.

In conclusion the author draws attention to Government recognition of the meritorious contribution of the Lighting Industry to the war effort and the official measures introduced to assist improvements to artificial lighting. He hopes that many of such welfare measures, found possible in war, may be continued in peace.