Light, photometry and illumination : a thoroughly rev. ed. of ''Electrical illuminating engineering'' (1912)
Barrows, William Edward, 1878-1960 · New York ; London : McGraw-Hill Book Co. · leaf 197
sexplained above, is illustrated in Fig. 105. The 15 lamps arelocated at 1, 2, 3, etc., as shown. It will be seen that the four-fourths of the room are similar, consequently one-fourth of theroom may be divided into sections and readings taken at a, b, c,d, etc., to obtain the average intensity for… … Fig. 106.—Areas and test stations for circular equi-luminous areas. direction from beneath the source may be chosen along which theillumination may be measured, and the average intensity calcu-lated from these readings. The locations of test stations for asurvey of this nature are shown in Fig. 106…
Light · Photometry · Electric lighting
Internet Archive · Boston Public Library · Public Domain Mark 1.0. Free to use for anything.
