Rich Nute does not agree with my assertation that it is not be feasible to include IEC 601 in a unified safety standard. This discussion is, of course, dependent on how much of the structure of existing standards we discard.
I have no doubt that general principles for a unified safety standard could be drawn up to include IEC 65, IEC 950, IEC 1010, IEC 601, IEC 335 and many other current standards. It may be interesting to move the emphasis of this discussion away from the technical details and towards the logical structure of such a standard, or family of standards. IEC 601 and IEC 335 each have many particular standards (IEC 601-2-XX and IEC 335-2-XX). If we use this model we would have a three-tier structure, with Level 1 covering general requirements, Level 2 covering product groups, and Level 3 for specific requirements for product types. Though this is a neat logical structure, my concern is that it may be unwieldy to use. Understanding a specific paragraph would involve referring to three standards simultaneously, with the lower levels adding to, amending or even cancelling the paragraph in higher levels. Another model is the use of generic standards, as in EN 50081-1, etc.(EMC standards), which refer to and fix test levels for other standards (e.g. the late IEC 801 series), which are in fact test methods. However we know that in this case the direction today is away from generic standards in the EMC field. Product specific standards take precedence over the generic standards, and more product specific standards are appearing all the time. However, even the EMC product specific standards generally refer to and fix test parameters for the 'test method' standards. Maybe this is a suitable model for safety standards. I have not come to any specific conclusions on this subject, but I would be interested to hear the opinions of other maling list members. Jon Griver ITL (Product Testing) Ltd. [email protected]
