This reaches back a bit and I hope you'll forgive my tardy entrance. I come from a test house background and would like to shed some light on certain assertions made in this thread.
Scott Douglas tells us, "In my years of being a compliance type, I have found many cases where I could not get an agency or test house to make a bold statement about this or that. Often one can accept that and understand why they will not commit. For one reason, they do not want to be the one sued by some disgruntled customer because something happened (or didn't happen). But just as often, I have found it extremely frustrating that I cannot get a straight answer from the same people." It's also important to keep in mind that anything said by the engineer might be contradicted, when presented to their reviewing engineer, leading to personal embarrassment. A bad decision could also lead to a precedent that is difficult to be rid of. Mulling things over is good for all concerned, especially the public's safety. I do agree, though, with Scott's advice to question anything that doesn't make sense. Insisting on clear engineering rationale is good practice and will even help the test house engineer maintain clarity. Sometimes the (unsatisfying) answer might only be "it's a compliance issue," implying a standards revision is called for. Chris Maxwell advises, "Personnel at a lab may deal with the same standard everyday. They should know the standard like the back of their hand." This is sometimes true and sometimes not true. In one department, I recall handling an average of 15-25 and as many as 40 projects at any given time, usually with little customer or technology overlap, often with only a little overlap in product standard. [In the case of industrial control equipment, the range covered products are so broad that it can be daunting to know even half of what an "expert" might need to know; a good understanding may be more difficult to muster (thank goodness for dash standards - a relatively recent innovation).] At any given time, for example: relays, branch circuit breakers, cartridge fuses, Class 2 transformers, unit substations, pool and spa equipment, panelboards, energy management equipment, printed wiring boards, general purpose transformers...the list goes on. It can be a juggling act to keep the requirements clearly in mind for any particular product and standard, especially in busy times. There are also relatively new employees that are still cutting their teeth on a standard, those that transfer between departments that handle different products and have to learn new standards, almost anything of the ilk. Nevertheless, there are some groups within these organizations that deal with relatively few standards and perhaps the back of the hand idea applies (for instance, ITE and telecom equipment, polymeric materials), but it depends sharply on the internal structure of the test house and how they run their businesses. The odds are great that we'll all act the teacher to test house engineers in our careers. Many serving on standards making panels on this forum fulfill this function regularly. Chris is right, though, that it can make a big difference if the test house engineer is familiar with a customers products and design philosophy. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"