File:Pacific Gas and Electric magazine (1912) (14597417797).jpg

Identifier: pacificgaselectr41913paci (find matches)
Title: Pacific Gas and Electric magazine
Year: 1909 (1900s)
Authors: Pacific Gas and Electric Company
Subjects: Pacific Gas and Electric Company Electric utilities Public utilities
Publisher: (San Francisco, Calif.) : Pacific Gas and Electric Co.
Contributing Library: San Francisco Public Library
Digitizing Sponsor: San Francisco Public Library

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Some six years ago the writerperfected a special method fortesting Watthour Meters in thelaboratory, testroom or on con-sumers premises, which has beenadopted since by a number oflighting companies on this Coast.It was described in the May, 1910. issue ofthe Pacific Gas and Electric Magazine andpublished by Shephard and Jones in theirbook entitled The Watthour Meter. In this method of test a timing device isused to measure the time required for the disk The timing device used so far in the prac-tical application of this method has been aspecial stop-watch, the large hand of whichmakes one revolution in one hundredth of anhour; the face of the watch being divided intenths called Millihours and tenths thereofgiving a hundred division dial. It has the ad-vantage that the accuracy of the meter undertest can be read directly off the watch aftertiming, therefore eliminating all elaborate cal-culation. It was noted after using this method foryears on all classes of work, that for labor-
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of a meter to complete one, two, or three atory and standardizing work, a more accur- revolutions with an applied load in watts or ate timing device would be desirable for one, two, or three hundred times the disk con- higher class work than the Millihour stop- stant K. This time interval for a correct watch. This watch was sufficiently accurate meter is supposed to be one hundredth of an for commercial testing, but for precision work hour, because was unsuitable due to time errors particularly (100 K) WattsX ^hour = K. Watthours. when starting. 127 A,. Pacific Gas and Electric Magazine To meet this requirement the writer de-signed a MilHhour Stop-pendulum (makingone cycle in I .1 000 hour, or one Millihour)which possesses all the advantages of abso-lute time accuracy, and has no starting errorswhatever. This Stop-pendulum has provenas simple in manipulation as the stop-watch;it is used not only for laboratory precisionwork, but also for commercial shop testingand, further, for checki

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