Emission Testing

Emission testing is an essential aspect of complying with all EMC legislation around the world.

 

The point of performing emission testing is protect the radio spectrum to enable radio services to operate and to ensure that electrical interference is minimised. Most interference testing however is a function of immunity testing.

Most EMC standards throughout the world are based on a CISPR standard (the International Special Committee on Radio Interference) . as indicated in the name, CISPR is a special committee of the IEC (International Electrotechnical Commission) whose remit is to prepare and issue standards for various product types such that radio services are protected.

TRaC holds UKAS accreditation to ISO17025 for many of the CISPR and subordinate standards as listed below

Typical Products

CISPR is organised into subcommittees which are based on the phenomena and product types as highlighted below.

SC A (CISPR/A)

Radio-interference measurements and statistical methods, covers radio-interference measurements and statistical methods and is responsible for the CISPR 16 series of standards. It specifies EMC instrumentation, EMC measurement techniques, uncertainties, statistical methods and limit modelling. At present, it is working on improving existing standards as well as developing new methods and techniques.

EMC emissions testingSC B (CISPR/B)

Interference relating to industrial, scientific and medical radio-frequency apparatus, to other (heavy) industrial equipment, to overhead power lines, to high-voltage equipment and to electric traction, handles interference relating to industrial, scientific and medical RF (Radio Frequency) apparatus.

SC D (CISPR/D)

Electromagnetic disturbances related to electric/electronic equipment on vehicles and internal combustion engine powered devices, deals with EM (Electromagnetic) disturbances related to electric and electronic equipment on vehicles and devices powered by internal-combustion engines.

SC F (CISPR/F)

Interference relating to household appliances tools, lighting equipment and similar apparatus, covers interference relating to household appliances, tools, lighting and similar equipment.

SC H, (CISPR/H)

Limits for the protection of radio services, sets the levels for each different product type or family of devices depending on use and develops generic emission standards.

SC I, (CISPR/I)

Electromagnetic compatibility of IT equipment, multimedia equipment and receivers, made up of the former SCs E and G, deals with the EMC of ITE (Information Technology Equipment), multimedia equipment and receivers, and is working on new emission and immunity standards. ITE includes audio, video and/or broadcast receiving equipment or a combination of these functions, such as radio and television receivers, audio amplifiers, DVD players, portable entertainment devices, for example, CD players, computers and peripheral equipment, routers, hubs and switches, telecommunication equipment, gaming machines, audio/video equipment intended to be mounted in vehicles, electronic musical instruments.

Regulatory Testing

As indicated above virtually all EMC standards find their origins in CISPR standards irrespective of their actual name. FCC Part 15 and 18 (USA) for example are derived from CISPR 16, 11 and 22.

This is a great benefit to manufacturers since it largely harmonises the technical requirements for many different markets and hence fixes one design. Testing at TRaC minimises costs further for many products since TRaC holds accreditation in many countries enabling one set of measurements to satisfy many different country's requirements.