Electricians' operating and testing manual; a hand book for men in charge of electrical apparatus, repair men, trouble men, lamp trimmers, and electricians generally (1916)
Horstmann, Henry Charles, Tousley, Victor Hugo, 1875- joint author · Chicago, F.J. Drake & co · leaf 298
sted annually because owners and opera-tors do not understand the loss of energy caused bycontinuing lamps of low efficiency in service. There are two very simple methods of measuringcandlepower; one of these is known as Rumfords, andis illustrated in Figure 176. A suitable pencil is setup about 2… … Fiorure 176 G then set up in such a manner as also to cause the pen-cil to cast a shadow upon the same screen but at adifferent angle from the other. It will be noted thateach lamp illuminates the shadow made by the otherand that when the intensity of the two lights at thescreen is equal, the…
Electrical engineering · Electric testing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
