IEEE C63.12

Abstract

Foreword<br>The problem of electromagnetic compatibility has existed from the early days of radio when spark gaps were used for transmitting and receivers picked up many signals unintentionally. Radio transmission has evolved from those early days into a highly sophisticated science. However, other c o nmeepda tibility is even greater today than it was in earlier times since modern society has come to depend on radio waviens all facets of life, from garage door openers and licensed broadcasting to sophisticated airplane and missile guidance systems. The proliferation of unintentional radiators, such as personal computers and video games, has increased the need for electromagnetic compatibility. <br>The need for an electromagnetic compatibility document was recognizebdy the American National Standards Committee C63 and as a result, the first official issue of C63.12 was approved 2 December 1983 and published by IEEE in 1984. Changes in national and international standards since that time prompted Committee C63 to request that Subcommittee Number 1 undertake a first revision, which was published by IEEE in 1988. Further changes in international andi n military immunity techniques and requirements, as well as requests by potential users of C63.12, led to the current revision. <br>This recommended practice suggests emission limits based on maintaining existing ambient levels and protection of licensed radio services. Immunity limairtes based on ensuring satisfactory equipment operation in the presence of likely disturbance levels due to man-made and natural noise sources. <br><strong>Scope</strong><br>Over the years many electromagnetic compatibility measurement and control standards have been developed. Many of these are of concern to particuclalar sses of devices such as receivers, transmitters, incidental radiation devices, etc. In establishing limits, it is necessary to relate the measurement technique that is used to determine compliance with a given limit to the field conditions under which the device being controlled will actually operate. This recommended practice presents a rationale for developing limits¹ and recommends sets of limits that are representative of current practice. These limits may be adjusted in particular applications as circumstances dictate. <br>As part of the development of limits, the following parameters should be considered: <br>a) The general properties of both man-made and natural environmental electromagnetic noise (disturbances)² <br>b) An understanding of the devices commonly used for measurement of such disturbances and their properties, which will assist the practitioner in selecting such equipments and associated measurement techniques for the particular application <br>c) The rationale that can be used in selecting a consistent seot f limits for emission and immunity (susceptibility), subject to various environmental constraints (good engineering practice) <br>These practices are intended to be applicable to individual equipments as well as systemosf various sizes and, if properly applied, will provide guidanfcoer obtaining both intrasystem and intersystem compatibility. <br>This recommended practice is organized as follows: Clause 2 references instrumentation and measurement methods; Clause 3 contains a list of definitions; Clause 4 describes environmental radio noise; Clause 5 describes the selection of measurement parameters; Clause 6 discusses limit setting; and Annex A is a bibliography.<br>¹ It should be noted that the limits and measurement techniques described herein are proposed for general use to the extent that they are not covered in the regulations of the United States federal government agencies. Clearly, in circumstances where such regulations apply and could be considered to be in conflict with these practices, those regulations take precedence.<br>²&#160;The terms radio noise, electromagnetic noise, and electromagnetic disturbance generally connote the same phenomena, except that radio noise is restricted to phenomena at frequencies above 9 kHz. Otherwise, these terms are used interchangeably in this document.