History of CISPR

The history of the International Special Committee on Radio Interference (CISPR) is one that extends over 75 years. There have been papers written over the years on its history. The one that is used as the basis for this article was presented at the 2005 Zurich EMC Symposium. The title was “A History of the Evolution of EMC Regulatory Bodies and Standards”, written by the authors of this article [1]. Manfred provided the majority of the research on CISPR up to the time of the Zurich symposium and Don continued the history up to the present time. This article will then present a brief history of CISPR from its inception to the present time.

History of the CISPR
There was general agreement that the most important international problem was to secure uniformity in the methods of measurement and in the specification of limits to avoid difficulties for the exchange of goods and services [2]. In 1933 an ad-hoc conference of interested international organizations was held in Paris to decide how the subject of radio interference should be dealt with internationally. It was agreed to form a Joint Committee of the International Electrotechnical Committee (IEC) and the Union Internationale de Radiotéléphonie (UIR, International Sound Broadcasting Union). The first meeting of the CISPR (then called “Comité International Spécial des Perturbations Radiophoniques” (only in 1953 in view of the importance of television, the last word was replaced by “Radioélectriques”) was in June 1934 in Paris, with representatives of six national committees of the IEC (Belgium, The Netherlands, Luxembourg, France, Germany and UK), the UIR and of other international organizations such as the International Union of Producers and Distributors of Electrical Energy (UNIPEDE), the International Conference on Large High Tension Electric Systems (CIGRE), the International Union of Railways (IUR) and of the World Power Conference. The Comité Consultatif International de Radio (CCIR) did not wish to become a full member. During the first meeting, two Subcommittees (SCs) (A on limits and B on measuring methods) were founded [3]. The proposal to “measure the high-frequency interference voltage at the terminals of the interfering electrical appliance” and to “evaluate the attenuation of the interference between the source and the input terminals of a receiver on the basis of statistical experimental data” was proposed by Germany and The Netherlands. International work continued until 1939 (with meetings held in Berlin, December 1934 and April 1935; in London November 1935 and May 1936; Brussels in March and December 1937; and in Paris in July 1939). The recommendations of CISPR were contained in the proceedings of the meetings and Reports RI Numbers 1 to 8 cover the period up to 1939.

The CCIR did not become a CISPR member, but later (in 1966) they adopted a recommendation (433), that as far as possible, administrations should take into account the recommendations, reports and publications of the CISPR and that national regulation concerning interference suppression should be based on the measuring methods and apparatus described by the CISPR. There was and is a clear division of work: interference between radio services or between transmitters of the same service is in the province of the CCIR (now ITU-R) and not the CISPR. The member nations of the ITU have signed the International Telecommunications Convention, urging the national administrations to keep radio interference levels as low as possible and which is a basis for national laws on interference suppression.

Agreement was reached on the CISPR delta network that makes it possible to measure the symmetrical (differential mode) and asymmetrical (common mode) component of the disturbance voltage [2]. In 1937, provisional limits were proposed for the symmetrical voltage of 3 mV from 160 to 240 kHz and of 1 mV from 550 to 1400 kHz and for the asymmetrical voltage of 1,5 mV both from 160 to 240 kHz and from 550 to 1400 kHz. In 1939, twelve copies of the first CISPR measuring receiver (designed in Belgium) were ready. Its frequency range included the long wave and medium wave bands (150 to 1500 kHz) and it had essentially the characteristics of today’s CISPR quasi-peak measuring receiver for Band B (0,15 to 30 MHz) with 9 kHz bandwidth and 1 ms charge time and 160 ms discharge time constant of the detector. However, the spread of results of measurement on a standard commutator motor in different countries was disappointing.

International CISPR work restarted in 1946 – now including a strong delegation from the USA. Canada, Japan and, since 1956, the USSR also took part in the meetings. In 1956, delegates from 17 countries took part in the meeting. In the meeting of 1946, it was recognized that measurements would be required for frequencies greater than 1.6 MHz and that major receiver design would be required for frequencies greater than 20 to 30 MHz. At this meeting the measurement of the RF voltage at the mains terminals of an appliance using the 150 Ω V-network was proposed [4]. In 1950, it was decided CISPR should be formally constituted as a special committee of the IEC [5]. The recommendations and reports continued to appear in the proceedings of the plenary meetings and the numbers RI 11 to 14 covered sessions in Paris 1950, London 1953, The Hague 1958 and Brussels 1959. Considerable progress was made on the specifications for measuring receivers and techniques for the frequency ranges 0,15 to 30 MHz and 30 to 300 MHz and both CISPR publications 1 and 2 appeared in 1961. In 1953, a steering committee was formed to aid the chairman and SC C on Safety Aspects of Interference Suppression was added. In 1958 eight working groups were established. Reference [2] gives the status of work up to 1970 as follows:

• WG 1 on Radio Interference Measuring Equipment which until 1967 defined all measuring receivers from 10 kHz to 1000 MHz including publications 1 through 4.
• WG 2 on Interference from ISM Equipment. Radiated emission limits were published as recommendations in the frequency range 0,15 to 1000 MHz.
• WG 3 on Interference from Overhead Power Lines and High Voltage Equipment.
• WG 4 on Interference from Ignition Systems and Internal Combustion Engines. Until 1970, limits were given for 30 to 300 MHz. At this time, limits were also considered up to 1000 MHz. Limits for interference to radio reception on the vehicle itself were under discussion, but it wasn’t until 1995 when CISPR 25 appeared.
• WG 5 on Interference and Immunity Characteristics of Audio and TV Receivers.
• WG 6 on Interference from Motors, Domestic Appliances, Lighting Apparatus and the like. Interference in the frequency range up to 300 MHz was a difficult item because different countries used different measurement methods, ranging from open site field-strength measurements, stop filter tuned supply cord substitution measurements, as well as earth current measurements to terminal voltage measurements. Finally, agreement was reached on a method proposed by Meyer de Stadelhofen of Switzerland, Chairman of the WG [6]. Limits were also approved for thermostatically controlled apparatus emitting discontinuous disturbance, e.g. irons and refrigerators using the counting of clicks and applying click weighting.
• WG 7 on the Impact of Safety Regulations on Interference Suppression. The chairman of this WG was a member of the IEC Committee on Safety (A.C.O.S.).
• WG 8 on Statistical Methods and Correlation between Measured Value and Disturbing Effect. A recommendation on the Significance of a CISPR limit was approved in Leningrad (1970) which implied that type approval may be made on the basis of measurements of a single sample whereas conformity of production should be ensured on a statistical basis.
• WG 9 on Terminology which contributed a chapter to the International Electrotechnical Vocabulary (IEV).
• WG 10 on Lists of Complaints. This was necessary in order to harmonize the national lists of complaints for better comparability.

In the period of 1961 – 1973 CISPR saw the appearance of Recommendations in Pub. 7 (1966), Reports and Study Questions in Pub. 8 (1966) and National Specified Requirements and Legal Regulations in Pub. 9 (1966). In addition to the Pubs. 3 and 4, Pub. 5 specifying the peak, average and RMS detectors appeared in 1968. In 1973, CISPR was reorganized by reconstituting the WGs as Technical SCs, each with its own national secretariat, thus sharing the administrative burden which hitherto had fallen on the CISPR secretariat.

Period 1973 to 1986. In 1973, the decision was made to incorporate all measuring receiver details and the common measurement techniques into one publication (No. 16) covering the work of SC A and to create self-contained publications including reports, recommendations and limits and specialised measurement methods. Thus, Pubs. 11 to 15 came into existence on the subjects of ISM, motor vehicles, radio and TV receivers, household appliances and fluorescent lighting and covering the work of SCs B, D, E and F. The work of SC C on high voltage lines appeared at a later stage in Pub. 18. It had also become evident that digital electronic equipment, microprocessors etc. could be a serious source of interference to radio reception and this was recognised in 1975 by creating a working group reporting first to the steering committee and later to SC B. This working group was reconstituted in 1985 as SC G with the terms of reference to include Information Technology Equipment. SC G was responsible for Pub. 22, the first edition of which appeared in the same year, doing away with the problem of NB/BB discrimination and establishing for the first time limits for QuasiPeak and Average detections in conducted emission measurements. The first international commercial immunity product standard was published in 1985 – Pub. 20 for the immunity of sound and TV broadcast receivers – to which the Italian NC provided many contributions [7].

Period 1987 to 2004. In these years, much effort was expended in the development of CISPR Pub. 16 to become “The CISPR Handbook”. Measurements in the field of EMC for a long time were known as an “estimation with expensive test equipment”. Therefore, the work concentrated on improving the reproducibility of measurements by adding requirements for test site validations, requirements for measurement uncertainty and by improving the definitions of the test methods and setups. Major steps forward were the publications of CISPR 16-4:2002 on measurement uncertainty and of reports on compliance uncertainty in CISPR 16-4-1:2004. SC G developed the CISPR 24:1997 “Immunity of ITE”, using the test methods in IEC 61000-4-x as basic standards. Also, SC F published CISPR 14-2:1997 “Immunity of Household Equipment, etc.” In 1999, CISPR created a new SC H on the development of limits. In 2000, SC C was dissolved and the merging of SCs E and G was decided to form a combined SC I taking into consideration that multi-media equipment was in the scope of E and G. Most of the CISPR work is well described by the publications developed from the early 1990s until the present day:

Generic emission standards:
CISPR 61000-6-3 Emission for residential, commercial and light-industrial environments
CISPR 61000-6-4 Emission for industrial environments

(From left) Ray Garret, a member of the Australian organizing committee of the CISPR meetings held in Sydney in 2007, as well as a member of the Australian CISPR delegation, is shown with Don Heirman, newly elected CISPR Chairman; Dr. Ralph Showers, head of the US delegation to the CISPR plenary meeting in Australia and past CISPR Chairman; and Peter Kerry, outgoing CISPR Chairman from the United Kingdom.

Don Heirman receives the prestigious Lord Kelvin award at the 2008 IEC General meeting in Sao Paulo, Brazil.  The then president of the IEC, Jacques Régis (left) of Canada, presented the certificate and medal to Mr. Heirman. Don follows in the footsteps of another well regarded CISPR Chairman, Dr. Ralph Showers, who received the Lord Kelvin award in 1998.  The award was first presented in 1995.

Period 2004-Present
CISPR continues to evolve with a focus on controlling the emissions from a wide variety of products as can be seen by the short descriptive titles of its publications noted above. A particular burst of activity has come from the need to expand the application to products that have multiple ways in which RF energy can be emitted. In addition, functions that heretofore were found in specific products have now been incorporated into modern consumer products. This has led to naming the merging of receivers and information technology into what is now termed “multimedia”. At the same time, there are many ways in which communication can now be sent, such as by incidental emissions from a microprocessor, to intentional emissions for radio services, to conveying information over a telecommunication port, to signal and control over the mains network.

The major activity in the past six years has been in the following areas (this list is not meant to be exhaustive but to give a broad perspective of the types of ongoing activities):

1. Specifying new test facilities (and appropriate emission limits) including fully absorber lined rooms (FARs), reverberating chambers, absorber lined (over the conducting ground plane) open area test sites (called the free-space open area test site or FSOATS), TEM waveguides, and those that are to be used for antenna calibration.
2. Expanding measurement instrumentation uncertainty into compliance uncertainty in applying test standards.
3. Defining better test instrumentation calibration, especially the calibration of antennas used to measure radiated emissions from products being tested.
4. Specific measurement techniques for complex products that define those with multimedia application (generally comprised of ITE and receivers).
5. Determining the interference potential and ways to control it when signals are placed on telecommunications cables and the mains (this is referred to as powerline telecommunications or powerline communications – PLT or PLC).
6. Addressing the emissions from automobiles and the concern for handling the electric vehicle charging system to ensure acceptable disturbance levels to radio services.
7. Incorporating EMC into such mega projects as SMART GRID to ensure the interoperability of this system in controlling the use of power.
8. Continuing the application of product immunity appropriately based on basic standards published by the IEC Technical Committee 77 (EMC).

The list goes on including maintaining test methods and limits for ITE, appliances, RF lighting, and industrial/scientific and/medical equipment. For further information on CISPR, visit: http://www.iec.ch/dyn/www/f?p=102:17:0::::FSP_SEARCH_TC:cispr. This web site has several links under “CISPR Dashboard” to contact the chairman and subcommittee chairs to see publications issued, and so forth. A link is also provided that identifies the national committees which are members of CISPR. The site http://www.iec.ch/emc/pdf/cispr_guide_2010.pdf provides guidance on the use of CISPR standards.

Next CISPR Meeting
To continue with all of its activity, CISPR works throughout the year mostly by electronic means and a smattering of face to face meetings. However, for conducting a full range of business, resolving major actions and reporting progress, an annual face to face meeting is held. At these meetings, over 200 technical experts and national committee representatives typically attend.

This year’s CISPR meeting will be in the United States in Seattle, Washington during October 6-15, 2010. Over 20 countries will be sending delegates including, of course, the US. This meeting will be held in conjunction with the annual IEC General Meeting where the business of the IEC is conducted along with that of up to 100 technical committees. The host is the US National Committee of the IEC. They have graciously accommodated CISPR’s request for meeting space and support to increase the success of the CISPR meetings. Attendees are assigned by their national committee as there is a need to clearly identify experts that are named by their national committee to participate.

Summary
This article has brought up to date the history of CISPR and how its standards were developed with an indication when key events occurred along the way. Its history is rich in accomplishments and service to the international EMC standards community. Challenges still remain. But the authors believe that when the CISPR history is updated in the future, clear progress in its EMC standardization work will be evident by the wide spread use of its standards.

Read Dr. Ray Showers’ Keynote Address “Electromagnetic Compatibility Comes of Age” given at the 1st Symposium and Technical Exhibition on Electromagnetic Compatibility held in Montreux, Switzerland, from May 20-22, 1975.

References

1. Heirman, D., Stecher, M.: “A History of the Evolution of EMC Regulatory Bodies and Standards”, International Symposium on EMC, Zurich, 2005.
2. Stumpers, F.L.H.M.: “International Co-operation in the Suppression of Radio Interference – The Work of C.I.S.P.R., Proc. I.RE.E. Australia, Feb. 1971.
3. Minutes of the first meeting of the CISPR 1934
4. Jackson, G.A.: “International EMC Cooperation Past, Present and Future”, IEEE AES Magazine, April 1987.
5. Jackson, G.A.: “The early history of radio interference”, Journal of the IERE Vol. 57 No. 6 pp.244 -250 (1987).
6. Meyer de Stadelhofen, J.; Bersier, R.: „Die absorbierende Messzange – eine neue Methode zur Messung von Störungen im Meterwellenbereich.“ Techn. Mitt. PTT (Schweiz) No. 3, 1969 (engl: “The absorbing clamp – a new method for the measurement of disturbances in the range of meter waves”).
7. Private communication between Manfred Stecher and Prof. Ermanno Nano, Italy.

Acknowledgement
IN Compliance would like to thank Janet O’Neil of ETS-Lindgren for her assistance in coordinating the publication of this article.

Donald Heirman is president of Don HEIRMAN Consultants – a training, standards, and educational electromagnetic compatibility (EMC) consultation corporation. He chairs, or is a principal contributor to, US and international EMC standards organizations including ANSI ASC C63® (chairman) and the International Electrotechnical Commission’s (IEC) Special International Committee on Radio Interference (CISPR) where in October 2007 he was named the chairman of CISPR moving from his previous role as its Subcommittee A chairman responsible for CISPR Publication 16. He is a member of the IEC’s Advisory Committee on EMC (ACEC) and the Technical Management Committee of the US National Committee of the IEC. In November 2008, he was presented with the prestigious IEC Lord Kelvin award at the IEC General Meeting in Sao Paulo, Brazil. This is the highest award in the IEC and recognizes Don’s many contributions to global electrotechnical standardization in the field of EMC. He is a past president of the IEEE Standards Association (SA), past member of the SA Board of Governors and past member of the IEEE’s Board of Directors and Executive Committee. Mr. Heirman may be reached at phone +1 732-741-7723 or by e-mail at d.heirman @ieee.org. For more information, visit www.DonHeirman.com.

Manfred Stecher was born in Munich, Germany in 1942. He received the Dipl.-Ing. Degree in electrical engineering in 1967 from the Technical University of Munich. In 1967 he joined Rohde & Schwarz, Munich. He was engaged in the development of EMI and signal monitoring test receivers and field strength meters, became group leader in 1980, and was responsible for the development of test receivers and accessories – hard and software. Since 1985, he has been a member of various German national standardizing committees on EMI instrumentation and measurement methods and since 1990 he has been an active member of various CISPR Subcommittees (mainly CISPR/A on measurement equipment and methods, but also CISPR/D and /I) and has contributed to ITU-R Study Groups on radio monitoring (mainly Study Group 1). He retired from Rohde & Schwarz in 2007. Presently he is Chairman of CISPR/A, the CISPR Subcommittee on EMI measurement instrumentation and methods. He has published approximately 150 papers in the field of EMI and signal monitoring. He holds several patents and has been awarded the DKE needle and the IEC 1906 award for his standardization activities. He is a senior member of the IEEE EMC Society and has been awarded a Certificate of Acknowledgement for contributions to the development and standardization of EMC measurement techniques. He may be reached by phone at + 49-8177-8632 or by e-mail at Manfred.Stecher @rohde-schwarz.com.