ETS-Lindgren 95242-1 Injection Probes - Manual (Page 21)

5.0 Conducted Emission: Transfer Impedance
The Bulk Current Injection Probe (BCIP) may also be used as a sensor for
measuring conducted emission. The RF current
I
P (in microamperes) in the
conductor under test is determined from the measuring receiver reading of the
probe output
E
S (in microvolts) divided by the probe transfer impedance
Z
T
(in ohms).
I
P
= E
S
/ Z
T
Or, in dB:
I
P
(dBµA) = E
S
(dBµV) – Z
T
(dB)
The transfer impedance is determined by passing a known RF current
I
P through
the primary test conductor and noting the voltage
E
S developed across a 50 ohm
load on the probe output.
Z
T
= E
S
/ I
P
Calibration gig 95241-1 may be used for this determination. Following are the
typical transfer impedance values when the BCIP is used as a sensor.
High sensitivity and minimal core gap indicate that the current probe
should be used only on signal lines where heavy currents are not
encountered. Heavy currents may affect measurement accuracy
should current probe core saturation occur.
Conducted Emission: Transfer Impedance | 21