420 



TABLE 428.— MAXIMUM DIAMETER OF WIRES FOR HIGH-FREQUENCY 

 RESISTANCE RATIO OF 1.01 



Frequency -=- 10» 0.1 0.2 0.4 0.6 0.8 1.0 1.2 1.5 2.0 3.0 



Wavelength, m 3000 1500 750 500 375 300 250 200 150 100 



Diameter in cm 

 Material r * \ 



Copper 0356 .0251 .0177 .0145 .0125 .0112 .0102 .0092 .0079 .0065 



Silver 0345 .0244 .0172 .0141 .0122 .0109 .0099 .0089 .0077 .0063 



Gold 0420 .0297 .0210 .0172 .0149 .0133 .0121 .0108 .0094 .0077 



Platinum 1120 .0793 .0560 .0457 .0396 .0354 .0323 .0290 .0250 .0205 



Mercury 264 .187 .132 .1080 .0936 .0836 .0763 .0683 .0591 .0483 



Manganin 1784 .1261 .0892 .0729 .0631 .0564 .0515 .0461 .0399 .0325 



Constantan 1892 .1337 .0946 .0772 .0664 .0598 .0546 .0488 .0423 .0345 



German silver . . . .1942 .1372 .0970 .0792 .0692 .0614 .0560 .0500 .0434 .0354 



Graphite 765 .541 .383 .312 .271 .242 .221 .197 .171 .140 



Carbon 1.60 1.13 .801 .654 .566 .506 .462 .414 .358 .292 



Iron ^ = 1000 00263 .00186 .00131 .00108 .00094 .00083 .00076 .00068 .00059 .00048 



M = 500 00373 .00264 .00187 .00152 .00132 .00118 .00108 .00096 .00084 .00068 



M— 100 00838 .00590 .00418 .00340 .00295 .00264 .00241 .00215 .00186 .00152 



SMITHSONIAN PHYSICAL TABLES 



