PYROLYTIC FILM RESISTORS: CARBON AND BOROCARBON 



311 



with temperature coefficients of resistance not exceeding 100 PPM deg C~\ 

 a representative value for high-resistance wire-wound types. 



10,000 

 8000 



6000 

 5000 

 4000 



3000 

 2000 



1000 

 ^n 800 



Q 600 

 z 500 



UJ 400 



O 



z 



< 300 



to 



tn 



lij 



cr 200 



2 



100 

 80 



60 

 50 

 40 



30 

 20 



-50 -100 -150 -200 -250 -300 -350 -400 -450 -500 -550 -600 

 TEMPERATURE COEFFICIENT OF RESISTANCE IN PARTS 

 PER MILLION PER DEGREE CENTIGRADE 



Fig. 24 — Dependence of the temperature coefficients of resistance for borocarbon films 

 of different resistivities on film resistance. 



The maximum film resistance normally used in production of carbon fihn 

 resistors is between 10^ and 10^ ohms, but much higher resistances can be 

 employed with borocarbon films. Thus, in Fig. 25, data for film resistances 

 of about 8 • 10^ ohms are given, and fihns of 10^ ohms have been successfully 

 produced. The temperature coefficients of resistance for such films are, of 



