What Is Electromagnetic Compatibility - C63?

Electromagnetic Compatibility C63, commonly written as ASC C63 or simply C63, refers to the Accredited Standards Committee C63 on Electromagnetic Compatibility, an ANSI-accredited body that develops voluntary American national standards for measuring electromagnetic interference and verifying the electromagnetic compatibility of electrical and electronic equipment. The IEEE Standards Association serves as the secretariat for the committee, and the resulting standards are co-branded as ANSI/IEEE C63 documents. C63 standards are incorporated by reference into Federal Communications Commission regulations and serve as the primary test methods used by accredited laboratories certifying electronic products for the United States market.

The committee traces its origins to the 1940s, predating the formal organization of both IEEE and ANSI in their current forms. It brought together engineers from government, industry, and academia who needed consensus methods for quantifying radio frequency interference and establishing a common framework for regulatory compliance.

Scope and Standards Development

The scope of ASC C63 covers the measurement of electromagnetic emissions and immunity across the frequency range relevant to commercial electronics, from below 1 MHz through the microwave bands. The committee operates through several subcommittees, each responsible for a distinct area: measuring instrument specifications, methods for testing digital devices and information technology equipment, wireless device test procedures, low-voltage power line communication standards, and specialized methods for vehicles and industrial equipment. Standards go through a formal ballot process that includes public review and adjudication of negative votes, a requirement of ANSI accreditation that distinguishes the C63 standards from guidance documents that have not passed that consensus procedure. An overview of the C63 standards family and its relationship to FCC rules is maintained by the ASC C63 secretariat at c63.org, the committee's official site, which lists active and superseded standards, subcommittee rosters, and public meeting minutes.

Key C63 Standards

Several C63 standards are particularly widely referenced in product compliance programs. ANSI C63.4 specifies the methods of measurement for radio noise and field strength in the range 9 kHz to 40 GHz for radio receivers and related equipment; it is the document most commonly referenced in FCC Part 15 enforcement and certification. ANSI C63.2 defines the specifications for electromagnetic interference and field strength measuring instrumentation, including measurement receivers, spectrum analyzers, and signal generators used in accredited test laboratories. ANSI C63.5 addresses antenna calibration and site validation, establishing how test sites are characterized and validated before they are used for compliance measurements. The ANSI Blog describes the scope and application of ANSI/IEEE C63.2 and explains how the instrumentation standard ensures that measurements made at different accredited laboratories can be compared with confidence. More recent additions to the family address wireless devices, unlicensed intentional radiators, and techniques specific to installed systems.

Relationship to FCC Certification

C63 standards occupy a unique position in the U.S. regulatory framework because the FCC relies on them rather than writing its own detailed test procedures. Equipment subject to FCC authorization under Parts 15 and 18 is tested using C63 methods at accredited Telecommunication Certification Bodies (TCBs) or at Accredited Test Laboratories (ATLs). Grantees of equipment authorization must retain test reports demonstrating compliance with the applicable C63 procedure, and those reports are reviewed if the FCC receives interference complaints or initiates an enforcement action. An update on the C63 standards family from Electronic Design magazine describes how revisions to C63 standards propagate into FCC rules through a rulemaking reference update, often with a transition period during which both the old and new versions are acceptable.

Applications

Electromagnetic Compatibility C63 standards have applications in a wide range of fields, including:

• Product certification for consumer electronics sold in the United States market
• FCC equipment authorization for unlicensed intentional and unintentional radiators
• Accredited laboratory qualification and proficiency testing for compliance test facilities
• Military and federal government procurement specifications that adopt C63 test methods
• International harmonization efforts between U.S. and international EMC standards bodies