File:The Street railway journal (1908) (14756841871).jpg

Identifier: streetrailwayjo311908newy (find matches)
Title: The Street railway journal
Year: 1884 (1880s)
Authors:
Subjects: Street-railroads Electric railroads Transportation
Publisher: New York : McGraw Pub. Co.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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instruments in connection withelectrolytic surveys of underground structures which arebeing conducted by the Electrical Testing Laboratories, ofNew York City. The graduations of this chart are arbi-trary. It was revolved once in 24 hours and was vibratedonce every 10 seconds. The zero position of the recordingarm was the middle of the scale, so that the record mightbe independent of the direction of the current, as in manycases the direction of the current changes from negativeto positive during the day. It is expected that by using anumber of these instruments, operating simultaneously atdifYerent points, stray currents in water and gas mains orin any underground structure may be recorded, making itpossible to discover the causes of trouble and how theymay be eliminated. The recording ammeter is shown in Fig. 2 connected toa standard Weston 10,000 amp. shunt, to which is alsoconnected a Weston indicating station ammeter. Thisillustration shows that the recorder may be readily applied
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FIG. 2.—RECORDING AMMETER CONNECTED TO SHUNT AND STATION AMMETER to any standard shunt which is already in service, withoutdisturbing the indicating instrument at the switchboard. Asillustrated here, leads of almost any desired length may beused to connect the indicating and recording instrumentsto the shunt on the main bus-bar. It is even possible tohave the recording ammeter located in the superintendentsoffice at a great distance from the shunt, and the indicatinginstrument located on the switchboard convenient for theobservation of the operator. Such combination outfits January i8, 1908.) STREliT RAILWAY JOURNAL. 93 could be furnished as units, with leads of the properlengths to suit the individual cases. The recording shunt annneter has been successfully ap-plied for taking continuous records of the current on a^ large trolley system, where the fluctuations are very rapid,and varied as much as 4000 amp. several times in a minute.The charts for such work as this are made to revo

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