Electrical measurementsA laboratory manual . ^ be joined in multiple orin series by the plugs so as to give a resistance betweenthe terminal binding-posts ranging from 2,500 to 250,000ohms. The plugs are slightly conical, and they should fitvery exactly in the conical sockets reamed out betweenthe ends of the adjacent brass blocks. Unless the fit isexact and the plugs are clean, the resistance of the con-. tact will not be negligible, especially with coils of smallvalue. The plugs should be kept very clean — freefrom dust, oxide, and grease. They may be cleaned byrubbing with a cloth dipped in
Electrical measurementsA laboratory manual . ^ be joined in multiple orin series by the plugs so as to give a resistance betweenthe terminal binding-posts ranging from 2,500 to 250,000ohms. The plugs are slightly conical, and they should fitvery exactly in the conical sockets reamed out betweenthe ends of the adjacent brass blocks. Unless the fit isexact and the plugs are clean, the resistance of the con-. tact will not be negligible, especially with coils of smallvalue. The plugs should be kept very clean — freefrom dust, oxide, and grease. They may be cleaned byrubbing with a cloth dipped in a very weak solution ofoxalic acid. In pressing the plugs into their placesa firm pressure should be used while the plug is slightlyturned; but great care should be exercised not to seatthem too rigidly or forcibly; otherwise their removalendangers their hard-rubber tops. Each resistance box is adjusted at some convenienttemperature wlnqh should be marked on the box. Cor- 28 ELECTRICAL MEASUREMENTS. rections may then be made to reduce to the resistancecorresponding to the temperature of the box, which isascertained at the time of use either by means of anattached thermometer, or by one passed through a holeprovided for the purpose in the cover. The blocks to which the coils are attached should bepierced with a tapering hole for special plugs with bind-ing terminals, so that each coil may be put
Size: 1783px × 1401px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherbosto, bookyear1895
