ETS-Lindgren 3160 Series, User Manual

Page: 26 / 70

26
| Radiated Emissions Measurements
The magnetic flux density
B
in (T) is related to the magnetic field
strength
H
in (A/m) by the permeability of the medium in (H/m). For
free space, the permeability is
µ
o
= 4
π
.10
-7
H/m. Converting from (T)
to (pT) and from (A/m) to (
µ
A/m) and taking the log, the constant
becomes:
240 120 20 4 10 2 0
10
7 − + × =
−
log ( ) .
π
dB(mW/m
2
) = dB(W/m
2
) + 30.0
dB(W/m
2
) = 10 log (V/m
•
A/m)
dB(pT) = dB(
μ
A/m) + 2.0
A/m = 10
dB ( A/m)-120
μ
20
E
QUATION
6
E
QUATION
7
E
QUATION
8
E
QUATION
9