In this second installment of a two part article, we continue our review of the recent meeting of IEC-CISPR held in October 2010 in Seattle. In the first part of this article, we have described the current changes affecting the basic standard CISPR 16 and the activities of its experts within CISPR sub-committee (SC) A. We now take a look at the activities of the other CISPR sub-committees responsible for preparing the CISPR product standards. We also describe some of the projects shared by CISPR and IEC TC 77B (High Frequency Phenomena).
Product Standards
CISPR SC B
Industrial, scientific and medical (ISM) standards
This sub-committee is responsible for the following standard:
- CISPR 11 – Industrial, scientific and medical (ISM) radio-frequency equipment – Electromagnetic disturbance characteristics – Limits and methods of measurement, 2009
Working Groups
- WG 1 – Industrial, scientific and medical (ISM) radio frequency apparatus
Amendment 1 to CISPR 11 Ed. 5: Selection criteria for the minimum separation distance between EUT and measurement antenna
- Proposal to replace the “Class” criterion currently used in CISPR 11 by a “size-of equipment” criterion. A measuring distance less than 10 m is allowed for “small equipment” either positioned on a table top or standing on the floor which, including its cables, fits into a cylindrical test volume of 1.2 m in diameter and 1.5 m above the ground plane.
Status: Final Draft International Standard (FDIS)
- WG 2 – Interference from overhead power lines, high-voltage equipment and electric traction
Status: The future CISPR 11, Ed 5.0 is currently under revision with key issues related to harmonizing methods with CISPR 16.
CISPR SC D
Electromagnetic disturbances related to electric/electronic equipment on vehicles and internal combustion engine powered devices
This sub-committee is responsible for the following standards:
- CISPR 12 Vehicles, boats, and internal combustion engines – Radio disturbance characteristics – Limits and methods of measurement for the protection of off-board receivers, 2009
- CISPR 25 Vehicles, boats, and internal combustion engines – Radio disturbance characteristics – Limits and methods of measurement for the protection of on-board receivers, 2008
An automotive EMC chamber for
whole vehicle testing per CISPR 25.
(Image courtesy of ETS-Lindgren)
Working Groups
- WG 1 – Protection of receivers used in buildings, along the roadside, or in outdoor areas
- WG 2 – Protection of on-board and adjacent vehicle receivers
- CISPR 25 Ed 3.0 2008-03
- Status: Ed 4.0 First CD 2010-11; CDV 2012-03; FDIS 2012 -11; Publication 2013-02
- The third edition of CISPR 25 Ed 3.0 announced several items for future work in annex I.
- Some items will be handled within the overall revision work of CISPR 25.
- The chamber validation methods (ALSE) used for the tests defined in CISPR 25 are a more complex issue, which is being addressed separately with the expertise of CISPR/A. The work on the fourth edition is therefore split up into two tasks with separate CDs. Depending on the comments received from the National Committees, the documents will be merged in the enquiry or approval stage.
CISPR SC A – CISPR SC D Joint Task Force (JTF)
Development of appropriate Fast Fourier Transform (FFT) methodology
- Joint Task Force between CISPR/A and CISPR/D – FFT-based emission measurement apparatus – Specification and application
Status: The work is essentially complete.
For details see CISPR A discussion in Part 1 of this article (IN Compliance Magazine, February 2011).
Development of a chamber validation method for CISPR 25
This Joint Task Force of CISPR D and CISPR A experts was assembled to develop a procedure for the validation of chambers used for radiated emission measurements made according to CISPR 25.
- The chamber validation procedure developed by the JTF would then be presented to CISPR/D as a proposed Annex for CISPR 25 4th Edition.
- As a secondary agenda, this JTF would also handle other chamber and site validation proposals for other CISPR/D specifications such as CISPR 12.
- The aim of this work is to
- Increase the reproducibility of measurements in such anechoic chambers,
- Be applicable in the frequency range between 150 kHz to 2500 MHz,
- Include the ground plane bench,
- Make use of the measurement antennas and their positions during CISPR 25 measurements,
- Be able to reference to established calibration environments (e.g. TEM cell, OATS),
- To specify measurement uncertainty for the site,
- Detect improper connection of the table to the floor or the wall of the ALSE, and,
- Give guidance on the minimum distances between the EUT and its wiring harness, and the chamber absorber material
The JTF has looked at currently used chamber validation procedures by the industry and also some custom procedures which have been developed for validation of chambers used for 1 meter radiated emissions measurements.
As a result, two chamber validation procedures have shown potential and could provide the CISPR 25 specification users some flexibility. It was thus decided that the proposed annex would contain two chamber validation procedures and the chamber performance can be determined by the use of either method (both methods are not required). The characterisation procedures are as follows:
- Reference Site Measurement Method: 150 kHz – 1 GHz
This method uses an OATS or Alternate OATS as a reference site. The measurements are made similar to Normalized Site Attenuation (NSA) measurements. The reference site measurements are then repeated in the shielded enclosure. The reference site measurements are then compared to the shielded enclosure measurements in order to determine if the shielded enclosure measurements are within a reasonable tolerance. - Modelled Long Wire Antenna Method: 150 kHz – 1 GHz
This method uses a 50 cm “long wire” antenna as the transmitting antenna. This long-wire antenna is then modelled with a ground plane of a standard size (2.5 m x 1 m). Measurements are then made on the long-wire antenna in the shielded enclosure. The shielded enclosure measurements are then compared to the modelled fields in order to determine if the shielded enclosure measurements are within a reasonable tolerance.NOTE: The “reasonable tolerance” has been proposed as:
The ALSE and its installation (physical layout, ground plane size, ground plane grounding, RF absorber, etc.) is suitable for testing, if the ∆ = Reference – Enclosure is within ± 6 dB for ≥ 90% of the data points across the entire frequency range of 150 kHz to 1 GHz.
Other Future Work
- Correlation to Japanese JASO –D002 standards: Experts from Japan have proposed a procedure to validate chambers used for radiated emissions measurements on vehicles. This is a proposed Annex for CISPR 12. Since this is a secondary project for this JTF, CISPR/D/WG 1 may decide to have this JTF work on this chamber validation procedure for them.
- Methods > 1 GHz
- Vehicle test chamber
Status: CD out for comment November 2010
CISPR SC F
Household Appliances, electric tools and similar apparatus
This sub-committee is responsible for the following standards:
- CISPR 14-1 Electromagnetic compatibility – Requirements for household appliances, electric tools and similar apparatus – Part 1: Emission.200
- CISPR 14-2 Electromagnetic compatibility – Requirements for household appliances, electric tools and similar apparatus – Part 2: Immunity – Product family standard.20
- CISPR 15 Lighting – SC F working with SC A on use of CDN (coupling-decoupling networks).
Working Groups
- WG 1 – Household appliances incorporating electric motors and contact devices
- WG 2 – Lighting equipment
Other Joint Task Force
- CISPR/CIS/A/JTF JTFA/F – Joint Task Force between CISPR/A AND CISPR/F – CDN measurement method of radio frequency disturbances for lighting equipment in the frequency range 30 MHz to 300 MHz
Status: CD in preparation
CISPR SC H
Limits for the protection of radio services
This sub-committee is responsible for the following standards:
- IEC 61000-6-1 (2005-03) Ed. 2.0 Generic standards Immunity for residential, commercial and light-industrial environments.
- Status Maintenance Result Date: 2011
- IEC 61000-6-2 (2005-01) Ed. 2.0 Generic standards Immunity for industrial environments.
- Status Maintenance Result Date: 2011
- IEC 61000-6-3 (2006-07) Ed. 2.0 Generic standards Emission for residential, commercial and light-industrial environments
- Status Maintenance Result Date: 2010
- IEC 61000-6-4 (2006-07) Ed. 2.0 Generic standards Emission for industrial environments
- Status Maintenance Result Date: 2010
Working Group
- WG 1
Status: Both generic emission standards are in the FDIS stage and will include emissions from 1 to 6 GHz similar to CISPR 22 but with a difference in the class A and B definitions. They will also include amendments for the use of FARs for floor standing equipment.
CISPR SC I
Information technology, multimedia, and receiver products
This sub-committee is responsible for the following standards:
- CISPR 13
- “Sound and television broadcast receivers and associated equipment – Radio disturbance characteristics – Limits and methods of measurement”, 2009
- CISPR 20
- Sound and television broadcast receivers and associated equipment – Immunity characteristics – Limits and methods of measurement, 2006
- CISPR 22
- “Information technology equipment – Radio disturbance characteristics- limits and methods of measurement”, 2008
- CISPR 24
- Information technology equipment – Immunity characteristics – Limits and methods of measurement, 2010
- Draft CISPR 32
- CISPR I/333/CDV Electromagnetic Compatibility (EMC) – Multimedia Equipment – Radio disturbance – characteristics – Limits and methods of measurements, 2012
- Draft CISPR 35
- CISPR I/330/NP Electromagnetic Compatibility (EMC) – Multimedia Equipment – Radio disturbance – characteristics – Limits and methods of measurement, 2013
Working Groups
- WG 1 – Methods of measurement and limits for radiation and immunity of broadcast receivers and associated equipment
- Maintenance of CISPR 13 and 20
- Current activity includes discussions on emissions from plasma TVs below 30 MHz and LTE interference in Europe. When this activity matures, it will be passed on to WG 4 for inclusion in CISPR 35.
Status: Stability period 2012
- WG 2 – Methods of measurements and limits for emissions from multimedia equipment
- CISPR 32 will combine and replace CISPR 13 and 22
- Since TEM Cells, Reverberation Chambers and Fully Anechoic Rooms were removed from the main body of the draft CISPR 32 Ed1.0, a number of separate CDs have been prepared that take them into account. They will be integrated into the main body if they are successful. These include:
- Proposed amendment of CISPR 32 outdoor units of home satellite receivers’ requirements.
Status: CISPR/I/347/CD for comment - Proposed amendment of CISPR 32 to included an informative annex on Gigahertz TEM and reverberation chamber emission test methods and limits
Status: CISPR/I/346/CD for comment - Proposed amendment of CISPR 32 Emission-test arrangement requirements for various types of multimedia equipment
Status: CISPR/I/348/CD for comment - Proposed amendment of CISPR 32 to include the FAR emission test methods and limits
Status: CISPR/I/345/CD for comment - Proposed amendment of CISPR 32 to specify which detectors should be used
Status: CISPR/I/349/CD for comment
- Proposed amendment of CISPR 32 outdoor units of home satellite receivers’ requirements.
- WG 3 – Methods of measurements and limits for radiation and immunity of Information Technology Equipment (Maintenance of CISPR 22 and 24)
- CISPR 22 Ed 6.0
- This standard is still within its stabilization period and not due for “maintenance” until 2012, but a few clarifications have been noted recently as below :
- Selection of average detector: CISPR 22 defines limits for radiated emissions at frequencies between 1 GHz and 6 GHz with respect to both average and peak detectors. CISPR 16-1-1 defines two types of Average detector for use above 1 GHz. For the limits given in CISPR 22, the appropriate average detector is the linear average detector defined in CISPR 16-1-1 Edition 2.2, clause 6.4.1.
- CISPR 24 Ed 2.0
- This new edition was published in August, 2010
- WG 4 – Methods of measurement and limits for immunity of multimedia equipment
Project Team: CISPR-22-PLT
Amendment 1 to CISPR 22 Ed.6.0: Addition of limits and methods of measurement for conformance testing of PLT (power line telecommunication) ports intended for connection to the mains
Despite the efforts of many technical experts over ten years, no proposed change to CISPR 22 for PLT has been able to generate the needed support among the National Committees and this project was reset to a preliminary level. Several national committees have put forward their own versions but the official agreed path is to now wait for the European EMC committee CENELEC to progress this issue. In the meantime PLT products are on the market across the world creating significant interference even though they are regarded as legal by the authorities.
such as televisions, per CISPR 22.
(Image courtesy of ETS-Lindgren)
Other activities
Work is starting in WG 3 to create amendments for both CISPR 22 and CISPR 24. They are at the DC (Draft for Comment) stage right now. At the time this article was written in mid-January, one is out for national committee comments for CISPR 22 and the other for CISPR 24 was expected by the end of January.
Other Joint Task Force Activity
- CISPR/CIS/A/JTF JTF A/I – Joint Task Force between CISPR/A and CISPR/I
- This was discussed under CISPR A in Part 1 of this article
Note that CISPR requires technical committees to provide justification for product standards that set different requirements than the generic standards and that use different test methods than those given in CISPR 16. The aim is to determine both differences and places where information contained within the basic standards is repeated in the product standard with the intention of providing an opportunity to justify or re-align and simplify these documents. First up was CISPR 22 largely because some of the work had already been completed in the CISPR/A CISPR/I JTF. CISPR 11 will be the next in line.
Summary of Joint Task Forces
IEC SC 77B / CISPR JTF work
IEC/CISPR has also set up a number joint task forces with IEC SC 77B with responsibility for the publication of the following:
IEC 61000-4-20 Ed.2.0: TEM waveguide test methods
This second edition of the standard has completed its first maintenance cycle and been revised to include field probe calibration as well as harmonized test setups for immunity and emission.
Status: Published
IEC 61000-4-21 Ed.2.0: Reverberation chamber test methods
This second edition of the standard has also completed its first maintenance cycle and is being revised to include, amongst other topics: field probe calibration, immunity and emission methods, and measurement uncertainty.
Status: Approved for Publication October 2010
IEC 61000-4-22 Ed 1.0 Fully Anechoic Rooms (FARs)
The methods described in this document offer an independent and more efficient method of validating a FAR and EUT set up for both radiated immunity and emissions which could exist in parallel to CISPR 16-1-4 and IEC 61000-4-3.
Status: Published
An example of a GTEM!™ test cell used to
perform both radiated emission and immunity tests
per IEC 61000-4-3 IEC 61000-4-20. (Image courtesy of ETS-Lindgren)
IEC 61000-4-20 Ed 2.0 IEC 61000-4-3 has been revised to include field probe (shown above) calibration as well as harmonized test setups for immunity and emission. (Image courtesy of ETS-Lindgren)
IEC/CISPR has set up a number of joint task forces with IEC SC 77B, including test methods using reverberation chambers, such as pictured above. (Image courtesy of ETS-Lindgren)
To independently and efficiently validate a Fully Anechoic Room (FAR), IEC 61000-4-22 Ed 1.0 provides a method for both radiated immunity and emission testing. (Image courtesy of ETS-Lindgren)
CONCLUSION
In summarizing both articles it is clear that much of the discussion has involved the activities of the CISPR A and CISPR I sub-committees. CISPR A deals with several different technical issues including the use of fast Fourier transforms (FFT), drafting a new antenna calibration standard and the integration of many of the test methods from the product standards as is now required by the CISPR management team. CISPR I is dealing with a number of issues related to real world changes in technology in multimedia and the major effort of bringing together the new standard CISPR 32 and 35, as well as dealing with the contentious subject of PLT. For more information, please consult the IEC website www.iec.ch including the EMC Zone on http://www.iec.ch/zone/emc or contact your national committee. 
Acknowledgements
The author wishes to acknowledge and thank Don Heirman, CISPR Chairman, for his invaluable review of and contributions to this article. He can be reached by e-mail at d.heirman@ieee.org.
About the Author
Martin Wiles BSC, MSC, MIEE is a Senior RF Engineer at ETS-Lindgren, in Stevenage, England. He represents the UK as a member of CISPR A. He can be reached by e-mail at martin.wiles@ets-lindgren.com.
