The question is posed; what is the wisdom behind all these standards? Indeed the are numerous standards that have been, are, and will be brought into existence effect every aspect of our various industries. The history of the beginnings of these regulates can be traced back to the events of the Titanic. As we move forward from this point we see that the number of electrical and electronics based equipment as spread from single end items, to necessary, critical, and life support interfaces and command and control devices. It is these reasons that make the control of emissions and the immunity from threats an absolute necessity.
My background covers both sides of the issue, that of testing for and complying with the various standards. While involved in the first it was my goal to establish a reputation through out the industry that when my or my colleges names appeared upon a test report it was understood that all due diligence had been exercised and the data reported was accurate. In pursuit of this, there were times when a client had to be made aware of the fact that their equipment was not compliant in its present state and then embark on a course to rectify the problems. There were no maybes, or if I do this to get by then I'll fix it of the next rev. If a client chooses to tightly encroach upon a limit, it is incumbent upon the test laboratory to inform them of such and document it. Integrity and pride of workmanship have no price. Working on the other side of the equation, it is only a change in that now the knowledge has to be spread across the design teams and other parts of the company. Once again though integrity takes precedence. This leads to the answer of the first question; what is the wisdom of these standards? Standards should change by the logical data supported arguments that are presented to industry and the committees. Yes there are standards which have outlive their usefulness and there are interpretations that may need review, but it will take the objective analysis of all aspects to implement changes. Until changes take affect, the are many sources of information available and EMC specialists to provide consultation. Use these in the evaluation and design phases to develop solid methodologies that prevent system level fixes, do not impact scheduling, prevent unplanned expenditures of reworking or redesigning, and eliminates the "why is compliance always a problem?" Below is an excerpt of a paper that I did for one of the groups that I support: EMC testing encompasses the measurement and verification of radiated emissions (RE), conducted emissions (CE), radiated immunity (RI), conducted immunity (CI), electrostatic discharge (ESD), electrical fast transients (EFT), and power line anomalies (surges, transients, and fluctuations.) These measurements are compared to standards set forth by FCC, CE (CISPR 22, CISPR 24, EN50082-1 et al.), VCCI, and CSA to prove compliance. Compliance to these standards is mandatory to be able to sell and export electronic equipment to our customers. Compliance to standards is only the beginning. As a component manufacturer we have no control of the final end-item, its manufacturing tolerances, or final configuration when in use. For these reasons, it is imperative to have as much margin between the demonstrated emissions and the applicable limit. For the same reasons, emissions margin is not the last aspect to be considered; identifying the immunity margin is as, or more important. More important in that as of July 01, 2001 it will be mandatory to comply with four additional immunity tests. As a note, the industry is already moving toward certifying to these standards. The question now would be; how does the quantification of margin help us? The quantification of margins provides us with a demonstrable measure of the effect our product will have on the performance of an OEM's end item. The OEM has the greater task of certifying a product; their situation being, they are integrating a system that must meet the same compliance standards. >From the system level view two things become concerns, 1) how do the emissions profiles of all components align (thusly contributing to the overall emission profile of the system) and 2) what component is the most susceptible to interference. The astute OEM's engineers will evaluate the components from which the system is to be assembled, scrutinizing them for performance and their compliance documents. It is at this point, performance being similar, that documented margin in the emission limits and testing above the required immunity standards can make the difference in our products being selected. Discounting the selection process of an OEM, ascertaining the margins and thresholds of susceptibility, provides us with recourse should a question arise. With data in hand we can establish that we have met and exceeded the base requirements for the market we are selling to and have only to question the quality control of our material vendors and the contract manufacturer. Further, as our scope of interest has changed to highly differentiated products the propensity for them to be used in instrumentation, industrial, or military area increases. These arenas have standards requiring elevated levels of immunity testing and in cases, more restrictive emission profiles over an extended frequency spectrum. By having established our product's capability we would be better positioned to execute a contract of this nature. <outbind://1/Image1.gif> JOHN E. STUCKEY EMC Engineer Micron Technology, Inc. Integrated Products Group Micron Architectures Lab 8455 West Emerald St. Boise, Idaho 83704 PH: (208) 363-5313 FX: (208) 363-5596 jestuc...@micron.com -----Original Message----- From: Martin Rowe (TMW) [ mailto:m.r...@ieee.org <mailto:m.r...@ieee.org> ] Sent: Friday, March 24, 2000 07:54 To: emc-p...@majordomo.ieee.org Subject: The wisdom behind all these standards I've been reading messages from this list for several months, and I see many questions about how to comply with the long list of EMC standards. Yet, I can't recall anyone ever questioning the appropriateness of any standard. That is, should the standard add value to a product or to those who use it? Is it that the EMC engineer's place is not to question the wisdom of a standard's value, but simply to make products with those standards, whether or not we agree with the intent of those standards? That's not to say that these regulations are bad. Maybe they're good because they make the world a better place for those who use electronic products. Just wondering. ---------------------------- /\ | Martin Rowe | / \ | Senior Technical Editor | / \ /\ | Test & Measurement World | / \ / \ /\ ____ | voice 617-558-4426 |/ \ / \ / \/ | fax 617-928-4426 | \ / \/ | e-mail m.r...@ieee.org | \ / | http://www.tmworld.com <http://www.tmworld.com> | \/ ---------------------------- ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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