EMC reference values and formulasEMC REFERENCE DATA Compiled by Henry W. Ott Revised 1998 No. 1 The following lists some of the more useful EMC formulas and approximations Electric Field Coupling Vn = 2 fC R V 12 T s π Approximate Capacitances Wire in bundle 40 pF/ft Twisted wire 20 pF/ft Center-Shield RG-58 33 pF/ft Center-Metal Tray 0.2pF/ft Pin-pin Amphenol 2 pF Man-AC power line 2 pF 1/2W Res., end-end 1.5 pF Shielding = Absorption Loss A(dB) = 9 thickness skin depth Radiated Field Strength AM: P(Kw ) E(V/m)= d(Kft ) FM & TV: E (V/M)=0.6E (for AM) Power Density to Volts/Meter E (V/m)= 3.77P(W / cm 2 ) 200 V/m 100 V/m 20 V/m 10 V/m 2 V/m 10mW / cm 2 3mW / cm2 100W / cm 2 30W / cm2 1W / cm2 Skin Depth (inches) f AI Steel 1 MHz 0.003 0.0003 10 MHz 0.001 0.0001 100 MHz 0.0003 0.00008 1000MHz 0.0001 0.00004 Field Stre……