384 



TABLE 386.— RESISTIVITY OF METALS AND SOME ALLOYS 



The resistivities are the values of p in the equation R = pl/s, where R is the resistance 

 in microhms of a length / cm of uniform cross section 5 cm 2 . The temperature coefficient 

 is a, in the formula Rt = R>[1 + aAt — f,)]. The information of column 2 does not 

 necessarily apply to the temperature coefficient. 



Tempera- 

 ture 



Substance Remarks °C 



Advance see constantan — 



Aluminum 20 



c. p. —189 



" —100 



" 



" +100 



" 400 



Antimony 



— -190 



liquid +860 



Arsenic 



Beryllium 20 



Bismuth 18 



— 100 



Brass — 20 



Cadmium drawn — 160 



" 18 



" 100 



liquid 318 



Calcium 99.57 pure 20 



Calido see nichrome 



Cesium — — 187 



— 



solid \ 27 



" _ liquid/ 30 



Chromium 



Climax 20 



Cobalt 99.8 pure 20 



Constantan 60% Cu. 40% Ni 20 



n 



u 



Copper annealed 20 



hard-drawn 20 



electrolytic —206 



" +205 



" pure 400 



" very pure, ann'ld 20 



Eureka see constantan 



Excello — 20 



Gallium — 



German silver 18% Ni 20 



Germanium — 



Gold 99.9 pure —183 



" — 



" pure, drawn 20 



" 99.9 pure 194.5 



la la see constantan 



Ideal " " 



Indium 



Iridium — 186 







+100 



Iron 99.98% pure 20 



" pure, soft — 205.3 



" " " —78 



" " " 



{continued) 



Temperature coefficient 



SMITHSONIAN PHYSICAL TABLES 



