ETS-Lindgren 94606-6 Current Probe - Manual (Page 43)

Operation | 43
Example:
Frequency is 10.0 kHz; step 1 measurement is 52 dB above
one microvolt. For example, suppose the transfer impedance of the
current probe used in the example was 8.0 dB below one ohm at
10.0 kHz. Then, as outlined in step 2: 52 dB + 8.0 dB = 60 dB above
one microampere at meter input.
I N T ERMS OF dB A BOVE O NE M ICROAMPERE PER M EGAHERTZ AT
M ETER I NPUT (B ROADBAND I NTERFERENCE M EASUREMENT )
1. Adjust the EMI test equipment for standard gain and make a peak
measurement of the broadband interference (voltage output from the
current probe) in terms of dB above one microvolt per megahertz. Use
procedures outlined in the EMI test equipment instruction manual.
2. Subtract the transfer impedance of the current probe in dB at the test
frequency from the dB measurement of the previous step. The result is
the value of the broadband interference in terms of dB above
one microamp per megahertz at meter input.
At meter input as used in the MIL-I-26600 and MIL-I-6181D
specifications refers to the current in the test sample lead.
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.
This result is beyond the limit of 46.2 dB above one microamp per
megahertz.