Following standards-the importance of keeping up

Most manufacturers are familiar with the official list of harmonised European standards for use under the self-certification route of the EMC Directive. This list is published from time to time in the Official Journal of the EC. It contains standards for the emissions and immunity performance of specific product types and, by means of generic standards, the emissions and immunity performance of most other product types also. But it is important to realise that the published list is subject to change. and there have in fact been three issues of the list since the Directive came into force in 1992. As new versions of standards have their titles published in the Official Journal, the manufacturer has to reexamine certification. Dates are specified in the revised standard showing withdrawal of previous versions and the period for which existing certification is valid. Specific standards are discussed, standards to be avoided are briefly mentioned, and the impact on design of the changing standards are discussed