STANDARDIZATION RULES OF THE A.I.E.E. 



369 



Distance. 



KilovolU 



R M S. 



5... 



10... 



20... 



25... 



30... 



35... 



40... 



45... 



50... 



60... 



70... 



80... 



90... 

 100... 

 110... 

 120. . . 

 130. 



APPENDIX E. TEMPERATURE COEFFICIENT OF COPPER 



360 The fundamental relation between the rise of temperature and the 

 increase of resistance of copper may be expressed thus: 



where R t is the resistance at any temperature / deg. cent.; #/, is the re- 

 sistance at any " initial temperature " (or " temperature of reference ") 

 ti deg. cent.; and Ot t is the temperature coefficient from and at the initial 



temperature t\ deg. cent. Obviously the temperature coefficient is dif- 

 ferent for different initial temperatures, and this variation is shown in 

 the horizontal rows of the table below. Furthermore, it has b 

 that the temperature coefficient is different for different conduct! 

 and that the temperature coefficient is substantially proportional to the 

 conductivity. The results of this simple law are shown by t: 

 columns of the table below. 



TEMPERATURE COEFFICIENTS OP COPPER FOR DIFFERENT INITIAL 

 TEMPERATURES AND DIFFERENT CONDUCTIVITIES 



