. The Bell System technical journal . resistance is approximately proportional tothe length; if interfiber resistances were large, the resistance per unitlength would increase considerably with the length of the threadmeasured. The above results also suggest that electrical conduction takesplace primarily through moisture in the interior of the fibers rather 2200 1890 1685 1685 2250 1970 Aver. 1942 230 BELL SYSTEM TECHNICAL JOURNAL than through moisture condensed on their surfaces. Other evidencesthat this is the case may be foun
. The Bell System technical journal . resistance is approximately proportional tothe length; if interfiber resistances were large, the resistance per unitlength would increase considerably with the length of the threadmeasured. The above results also suggest that electrical conduction takesplace primarily through moisture in the interior of the fibers rather 2200 1890 1685 1685 2250 1970 Aver. 1942 230 BELL SYSTEM TECHNICAL JOURNAL than through moisture condensed on their surfaces. Other evidencesthat this is the case may be found in the relationships of conductivityto humidity, moisture content and electrolyte content, as well asthe absence of any obvious relationship between the physical dimen-sions of different classes of fibers and their electrical behavior. TABLE II Resistance of Different Lengths of Cotton Thread Humidity about 77 per cent Room temperature Resistance MegohmsLength Inches Total Per Inch 21,700 43,400 1 41,750 41,750 3 153,000 51,000. 20 30 40 50 60 70 80 90 loo RELATIVE HUMIDITY— PER CENT Fig. 1—Dependence of moisture content of textiles upon relative humidity ofatmosphere with which they are equilibrated While the form of the sample is not of predominating importancewith reference to the insulation resistance of either cotton or silk,the marked contrast except at very high humidity between cottonand silk in all forms of samples should be noted. Both these factsand other available data justify the inference that the dielectricproperties of textiles are determined primarily by the composition or INFLUENCE OF MOISTURE UPON INSULATORS 231 internal structure of the fibers, not by the twist of threads or the layof servings. The moisture content of each sort of textile depends directly on thehumidity of the atmosphere. Fig. 1 shows the best data availablefor the moisture content of silk, wool, cotton, and cellulose acetate inequilibrium with air over considerable ranges of relat
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