437 



TABLE 454.— DIELECTRIC CONSTANT AND LOSS TANGENT OF DIELECTRIC 



MATERIALS 151 



The following table presents values of dielectric constant," e' (relative to that vacuum e ) and 

 loss tangent, tan 5, for various substances at the frequencies and temperatures indicated. The loss 

 tangent, tan 5, is identical with the power factor, cos 6 (or sin 5), for low loss substances. The 

 table shows it multiplied by 10*. 



Part 1. — Solids 



Temp. Frequency, cycles per second 



Materials "C 



A. Inorganic 



1 . Crystals 



Ice 1 * -12 



Sodium chloride 2 25 



2. Ceramics 



a. Steatite bodies 



AlSiMag211 8 25 



b. Miscellaneous 



Ruby mica* 26 



Mycalex K 10 5 24 



Porcelain, dry process 8 25 



3. Glasses 



Corning No. 790 7 20 



Corning No. 1990 8 24 



Foamglas 8 23 



Fused quartz 10 25 



B. Organic, with or without inorganic components 



1. Crystals 



Naphthalene 11 25 e'Ao 2.85 2.85 



tan 5 19 3 



2. Plastics 



a. Phenol-formaldehyde 



Bakelite BM-16981 12 25 e'Ao 5.05 4.87 4.72 4.62 4.52 



(powder preheated) tan 5 190 160 72 56 82 



Formica XX 13 26 e'Ao 5.23 5.15 4.60 4.04 3.55+ 



(field J. to laminate) .... tan 5 230 165 340 570 700t 



b. Phenol-aniline-formaldehvde 



Resinox 7013 14 .* 25 e'Ao 4.64 4.55 4.37 4.30 4.25 



(preformed and preheated) tan 5 160 137 62 77 124 



c. Melamine-formaldehyde 



Formica grade FF-41 15 



(sheet stock) 26 e'Ao 6.15 6.00 5.75 5.5 



tan 5 400 119 115 200 



Melmac resin 592 16 27 e'Ao 6.70 6.25 5.20 4.70 4.59 



tan 5 590 470 347 360 434 



d. Urea-formaldehyde 



Plaskon urea, natural" 24 e'/e„ 7.1 6.7 6.0 5.2 4.65 



tan 5 380 280 310 500 782 



e. Hexamethylene-adipamide 



Nylon 610 18 25 e'Ao 3.60 3.50 3.14 3.0 



tan 5 155 186 218 200 



Nylon 610 18 25 e'A„ 4.5 4.2 3.2 3.0 



90% humidity tan 5 650 640 380 220 



m These data were selected from Tables of Dielectric Materials, volume 3, Laboratory of Insulation Research, 

 Massachusetts Institute of Technology, Cambridge, Mass., June 1948. 



* e is used for dielectric constant in this table in the place of K. 



* Numbers refer to notes at end of table. 

 ** Not corrected for variations of density. 



t Rod stock in H u (TEn) made of circular wave guide. 



(continued) 

 SMITHSONIAN PHYSICAL TABLES 



