Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 144
y lost, and the flux in thelower hemisphere being only slightlyincreased. This, in conjunction withthe glare effect due to the insufficientcovering of the bare source, renders theunit very much less efficient thanwhen properly arranged. The necessity for sufficient coveringpower is frequently… … 240 Fig. 9.—Distribution curve of bare source andsame in green cased opal, plain opal, andenamelled steel shades. I 100 200 300 1 100 f i 1 \ X y \ \vX ^ fc 200 \ \ \\ * \ X^ :■ 300 \> V 400 \ 1\ I\ 1 \\ A 500 Li—- —n \^ Y 600 ^\ 71 HI / \/ \ / v —sIlvered \ GLASS ^,«--- \ 8U0 QUO / U- \ Fig.…
Lighting
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