Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 272
buildings, and sky shall be ex-cluded. (2) The height of the test-screen fromthe ground is immaterial. c. Requirements for an Illumination Photo-meter : (1) The test-i^late, if forming part ofthe i:)hotometer, shall be so arranged thatit may receive the sum of the illumina-tions of neighbouring… … 10 12 14 20 24 Height in feet Graph of Mr. H. T. IIarrison\s Table. from tlio cosino law. Up to the angle ofincidences of CO degrees this total varia-tion shall not, under working conditions,exceed 10 jx^r cent. (3) Provision shall be nia<le for holdinghorizontally, and at a lu-ifxli of 3 ft. 3…
Lighting
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