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BELL SYSTEM TECHNICAL JOURNAL 



It is experimentally impracticable, if not impossible, to determine the 

 noise and resistance of each contact in an aggregate; hence in the 

 experimental test of the foregoing equations we have, in effect, divided 

 the aggregate into unit cells. The aggregate of carbon granules was 

 placed in four parallel grooves cut in a single phenol fibre block. 

 Each groove was provided with five gold electrodes evenly spaced 

 along the surface of the groove so that there were, effectively, four 

 contiguous carbon cells in each groove. This permitted the measure- 

 ment of the noise from each cell separately and also from the cells in 

 various assemblages. Applying Eq. (6) or (7), as the case demanded, 

 to the values of the noise from the single cells we calculated the 

 expected noise of the assemblages and compared this with the measured 

 values. Table I gives typical results for parallel assemblages and 

 Table II typical results for series assemblages. 



TABLE I 



TABLE II 



