The performance & construction of the LISN is documented in CISPR 16-1. The line cord is not part of the discussion. Your test standard (BS EN 55022) specifies the setup and AC mains cord length.
To complicate matters, EN50022 doesn't _exactly_ call out an 1 meter AC cord. Paraphased it says: "use a 1 meter cord, or a longer cord folded back and forth to make 1 meter." I found this change can affect conducted emissions at the high end (20-30MHz). I asked a similar question concerning LISN correction factors last year. Above 1MHz, the EUT port/RF port correction factor is <1dB. On Wed, 19 Jan 2000 15:06:19 +0000, [email protected] wrote: >This is going to sound like a very naive question, and I almost don't want to >ask it, but exactly where is the mains port? > >The question comes from some work I've been doing on our LISN. I've used a >comparison noise emitter and a 1m mains lead (as required by BS EN 55022) to >measure the insertion loss of the LISN. I then connected the CNE directly to >the receiver and made a second measurement. At 150kHz, the results are very >similar (0.5dB difference), but at 30MHz there is something like 5.5dB >difference between the direct measurement and the 1m-cable-to-LISN result. > >So, if the mains port is the actual connector on the test item, do I have to >add >a correction factor for the interference loss in the mains lead? Or is the >mains port at the end of the 1m cable, in which case no correction factor is >required. Or have the standards bodies taken all this into account, and that >is >why they specify a 1m mains lead? ---- Pat Lawler [email protected] --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
