Conformity Magazine - July 2008 - (Page 22)

from CISPR/A and SC77B, is currently developing the standard IEC 61000-4-20 that will be discussed later in this article. The draft standard has included an informative annex on sampling size that the reader is recommended to read. Finally, it should be noted that an amendment to CISPR 16-14 [9] will be introduced on evaluation of the set-up table in the frequency range above 1 GHz. The purpose of this amendment is to provide a process to determine the impact of the setup table on the overall measurement uncertainty. At higher frequencies, the reflection properties of positioning equipment becomes more critical because it becomes electrically large. CISPR Product Standards Basic standards like the CISPR 16 series serve a wide base of requirements, one of which is to define measurement methods that are not specifically defined by product standards. Historically, there has not been a general practice of harmonization between the product groups, and this has led to some disparity in measurement methods. However, this is changing, and CISPR/I decided that CISPR 22 [10] in its 2005 revision would be one of the first product standards to remove much of its own text on chamber measurement methods and product measurement methods, and refer instead to CISPR 161-4 and CISPR 16-2-3. For radiated emission measurements above 1GHz, the following references are included: The measuring antennas shall be as defined in subclause 4.6 of CISPR 16-1-4, the measuring site shall be as described in subclause 8 of CISPR 16-1-4, the measurement method shall be as specified in subclause 7.3 of CISPR 16-2-3. More recently, this work has been progressed with the formation of a Joint Task Force between CISPR/A and CISPR/I that is working on the broader transfer of test methods from both CISPR 13 [11] and CISPR 22 into the CISPR 16 standards series. This will clearly serve as a pre-cursor to the proposed new Multimedia standard CISPR 32 [12], that will ultimately replace 13 and 22. We will discuss this standard later in the article. Other key CISPR standards, such as CISPR 11 [13] and CISPR 14 [14], are beginning to coordinate with the CISPR/A to harmonize methods and also to avoid the parallel development of different methods that could otherwise introduce different requirements. One standard remaining slightly isolated from this trend is CISPR 25 [15] for automotive products, for which CISPR/D is responsible. Measurement methods used by the automotive industry have traditionally been somewhat different in order to meet specific requirements. These differences cause chambers that meet the requirement called out in CISPR 25 to probably not comply with CISPR 16-1-4, with the result that these chambers can only be used for automotive testing. The recently published Edition 3 of the standard has simplified the dimensional requirements for the chamber, but still does not define a chamber validation method. A joint task force between CISPR/A and CISPR/D is working on such a method to be published within the next 5 years. However, it is unlikely that CISPR 25 would eventually refer chamber validation to CISPR 16-1-4; the needs of the automotive industry will require the development of an independent method and therefore define different chamber requirements. Figure 9: CISPR 16-2-3 discussion height scanning with tilting Figure 10: CISPR 16-2-3 discussion height scanning without tilting 22 Conformity JULy 2008

Table of Contents Feed for the Digital Edition of Conformity Magazine - July 2008

Conformity Magazine - July 2008 Contents Editor's Note FCC Adopts 6 Million Dollars in DTV Enforcement Orders Commission Enforcement Bureau Adopts V-Chip Consent Decree FDA Seeks 2 Million Dollars from Medical Device Manufacturer FDA Answers Questions About CFLs and UV Radiation EPA Issues Energy Star Specs for TV, Video Boxes Canada Unveils Sweeping Product Safety Legislation How the Evolution of CISPR Standards Continues to Shape the Requirements for Anechoic Chambers ESD Open Forum Reach Compliance for Non-EU Article Manufacturers The iNARTE Informer Preamplifier Considerations for Emission Measurement Systems Effective Shielding in Medical Electronics Applications Product News Focus On...Power Components Buyer's Guide Updated Standards List for the EU's ATEX Directive EOS/ESD Symposium Set for September CPSC Actions in the News Researchers Work to Develop Non-Flammable Batteries Safety Link Launches Redesigned, Enhanced Web Site IEC Standards Update UL Standards Update Product Reviews Telcordia Standards Update From Our "You Can't Make This Stuff Up" Department Looking Back: Items from Past Issues of Conformity Advertisers

Conformity Magazine - July 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.