Are you familiar with CISPR 32 and CISPR 35? CISPR 32 was originally published in 2012, followed by a pair of corrigenda and then the 2nd edition was published in 2015. CISPR 32 replaced CISPR 13 (Broadcast receivers emissions) and CISPR 22 (ITE emissions), both of which were withdrawn by the IEC on March 5, 2017. In the EU CISPR 32 is published as EN 55032 and it has superseded EN 55013 and EN 55022. By now you should all be comfortable with CISPR 32 and your labs should be using it.
Likewise, CISPR 35 was published in 2016 and replaces CISPR 24 (ITE immunity). It ultimately will replace CISPR 20, as well. CISPR 20 and CISPR 24 will be withdrawn by the IEC on July 31, 2020. In the EU CISPR 35 is published as EN 55035, and it has superseded EN 55020 and EN 55024. Korea adopted its own version of CISPR 35 a while ago, but their standard is based on the Committee Draft for Vote (CDV) that resulted in a Final Draft International Standard (FDIS) that failed in voting in CISPR SC I. Confused yet?
It will only get worse. As noted in a previous blog on changes to CISPR SC I standards I mentioned a scene from the original Star Trek movie where Bones McCoy comes aboard the newly remodeled star ship Enterprise and goes off mumbling about having to look at the new sick bay. He knows it will be different, “I know engineers. They love to change things!” I’m sure whoever wrote that line had been around engineers, because it is true. We love to change things. That’s what we do. It’s still true, and it always will be true.
Why do I bring this up? Because, guess what? Changes for CISPR 32 and CISPR 35 are afoot. Amendment 1 to CISPR 32 Edition 2 was just published in October 2019. CISPR 35 Edition 2 is being worked in CISPR SC I MT8, but won’t be published for a couple for a couple years yet.
So, what’s changing (or has changed)?
CISPR 32
CISPR 32, Edition 2, Amendment 1 was published in early October 2019. This amendment is rather lengthy and covers a wide range of topics. The simple ones are:
- A change to the scope of the standard to clarify wording relating to radio communications devices and to clarify what equipment is not covered by the standard.
- Normative references are updated.
- The note to clause 3.1.30 (signal/control port) is updated.
- The abbreviation “PSD” was added and defined. “Power Spectral Density”
- The third bullet in clause 6.2 was replaced.
- The second bullet point of the last list was updated to show the latest edition/amendment of CISPR 16-4-2.
- Clause 11 was replaced in its entirety and now requires the full implementation of the measurement instrumentation uncertainty requirements in CISPR 16-4-2.
- Annex A has multiple changes and additions. A key change is the limits from 1 GHz to 3 GHz (raised by 4 dB) and a change to the measurement procedure requiring 1 m to 4 m height scans for all EUTs. No “bore sighting” is required.
- The notes to Table B.1 have been changed.
- A number of changes were made to Annex C, one of which will be corrected in the next Edition of CISPR 32. Which one is incorrect? That is left as an exercise for the student.
- There are a number of changes in Annex D. Too many to list here.
- A number of new Figures were added to Annex G.
- Annex H was replaced in its entirety. Unless you deal with satellite receivers, this isn’t important to you.
- Annex I has its reference to ANSI C63.4 removed.
- Annex J is added to the standard and deals with color bar images.
- New references are added to the bibliography.
All in all, the Amendment consists of 44 pages of changes. Ninety if you count the French version, as well. The best thing I can recommend is that you buy the Red Line version of CISPR 32 Edition 2.1 as it will show all the changes to the standard.
CISPR SC I MT7 is now beginning work on CISPR 32, Edition 3. The RMS-Average detector work was stopped last April in the MT7 meeting as not enough national committees support this work. A pair of items that have been discussed in the past will be circulated for comments by the national committee, along with a number of other items. One these items that has been discussed in the past deals with termination of the AC mains cables where they leave the measurement area and this is being dealt with by CISPR SC A. While Subcommittee A is working on amendments to the appropriate CISPR 16 standards and this work has not yet been completed, the termination of single phase mains cables will be included, at least initially, in this work. Wireless power transfer (WPT) work will also be included for national committee comments. In addition, the following items will be included in the CD to accompany the RR to be circulated “soon”:
- Radiated emissions limits from 6 GHz to 18 GHz.
- Consideration of limits in a reverberation chamber. This will require consideration of IEC 61000-4-21.
- Warm-up times for EUTs.
- How to test radio functions.
- DC power ports
- In-situ measurements
- TV tuner port updates
- Amplitude probability distribution (APD) function
- Satellite receiver conducted emissions testing below 950 MHz
- FAR limits and methods of measurement above 1 GHz
- Scope alignment with CISPR 35 related to radio functions
- Minor editorial items
CISPR 35
CISPR 35 was published in August of 2016. CISPR SC I MT8 is working on preparing a new edition of CISPR 35 that will address a number of issues that came up in the preparation of the original edition of the standard. There were one and a half days of discussions in MT8 in Shanghai about what should be changed and why. It was also decided that due to the number and nature of these changes that a new edition, Edition 2.0, of CISPR 35 will be the result.
One of the issues that has caused MT8 to keep the reference to an older edition of IEC 61000-4-5 is the belief that the current edition requires applying the surge to the antenna port of the EUT. It was shown that IEC 61000-4-5, in a note, excludes this. One of the changes in the CDV will be to specifically state that such testing is not required.
An area of contention and comments from national committees is the idea of direct and indirect functions. Direct functions are those that can be observed directly and indirect functions are those that can only be observed by observing a direct function. There is question about how you would actually observe an indirect function. More guidance will be included in the text of the CDV.
One item discussed was whether or not pulse modulation should be added to the standard, or if it should replace amplitude modulation. It was decided to make no change at this time and that further data will be needed before considering a change in the future.
A draft CDV will be circulated to MT8 members in the near future for the MT8 members to comment on. The current guidance we are getting from the IEC central office is that it takes five months from the time the text of a CDV is received until voting is complete. This is due to the time it takes them to create the actual CDV, have the French translation made (two months for that alone), send it out for vote and create the document tabulating the results of the vote. Hence, the current plan to have the MT7 and MT8 meetings in late June.
Conclusion
In conclusion, as noted in a previous blog, Bones McCoy was correct in his observation in the first Star Trek movie. Engineers do love to change things and CISPR 32 and CISPR 35 are not static standards. Don’t get comfortable with the standards as they exist today. Remember, CISPR 22 had six editions in its lifetime from 1985 to 2008. These standards won’t be any different.
