ETS-Lindgren 94456 Current Probe (Archived) - Manual (Page 15)

MODEL 94456 CURRENT PROBES Operation
© EMC TEST SYSTEMS, L.P. – MARCH 2002 11
REV B – PN 399265
interference in terms of dB above one microamp-per-
megahertz at meter input.*
Example:
Frequency is 100 kHz; Step (1) measurement is 41 dB
above one microvolt-per-megahertz. For example, suppose
the transfer impedance of the current probe was 8.0 dB
below one Ohm at 100 kHz. Then, as outlined in Step (2):
41 dB + 8.0 dB = 49 dB above one microamp-per-
megahertz at meter input. 2
This result is beyond the limit of 46.2 dB above one
microamp-per-megahertz .
In Terms of Microampere in Test Sample Lead
(CW Conducted Measurements)
1. Adjust the EMI test equipment for standard gain and
make a measurement of the CW signal (voltage output
from current probe) in terms of microvolts at meter
input. Use procedures outlined in the EMI test
equipment instruction manual.
2. Divide the microvolt measurement of Step (1) by the
transfer impedance in Ohms at the test frequency. The
result is the value of conducted CW signal in terms of
microamperes in the test sample lead.
Example:
Frequency is 3.0 kHz; Step (1) Measurement is 150
microvolts. For example, suppose the transfer impedance of
2 The term “at meter input” as used in the MIL-I-26600 and MIL-I-6181D specifications refers to the
current in the test sample lead.
Archived 6/1/10