Monday, July 12, 2010

EN 55013, QP vs RMS

An analog TV showing noise, on a channel with ...Image via Wikipedia
The EU Commission is holding off publication of the CENELEC standard, EN 55013: 2009, in the official journal, as a result of a negative opinion of the EMC CENELEC consultant.

Publication in the official journal is a required step for any standard to be considered a harmonized standard, for the purpose of conformity assessment, under new approach directives, in this case, the European EMC directive.

The published harmonized version, as of March 1, 2009, is EN 55013: 2001 +A2 2006.

The point of contention with EN 55013: 2009, is the introduction of an RMS average limit.

Traditionally, measurements are based on a Quasi Peak limit, and made using a “Quasi Peak” detector. Legitimate debates continue regarding the suitability of the specified Quasi Peak detector based system for high frequency measurements, or for gauging interference caused to modern digital systems. See Practical Paper “The Quasi-Peak Detector” By Edwin L. Bronaugh for more about the QP detector.

The consultant points out that the proposed RMS average limit offers a “major relaxation of the limits, up to 20dB”, and contends that protection of analog services will be significantly reduced.

The question that the commission is looking to answer now is what effect this limit change will have on equipment using analog technology, as it is assumed that newer digital equipment has a higher tolerance for increased interference levels.

The commission is seeking the EMC working group delegate’s input by August 23, 2010 on whether or not the new standard adequately protects the essential requirements of the EMC directive.

Thursday, July 8, 2010

Radio module integration and R&TTE compliance

Wireless UFO?Image by jepoirrier via Flickr

Compliance with the EU Radio and Telephone Terminal Equipment directive (R&TTE) is compulsory for radio devices. The responsibility for compliance is placed clearly on the manufacturer of the device. When integrating a radio module into a completed product, the integrator then becomes the “manufacturer” of the radio device. The underlying basis for this is that the integration of the two products can affect final compliance with the directive.

Technical reports from ETSI, ETSI TR102 070 parts 1 and part 2, give guidance related to the integration of radio modules into final product, already assessed for EMC, and the application of harmonized standards. These documents, together with the directive, form the basis of guidance notes developed by R&TTE notified bodies for the assessment of product to the directive.

In all cases, assessments must be made for compliance with R&TTE directive article 3.1(a), and 3.1(b). These articles cover Safety and EMC, respectively.

According to a quote in the guidance document;

“Assessed radio modules installed in equipment in conformance with the manufacturer's installation instructions require no further evaluation under Article 3.2 of the R&TTE Directive and do not require further involvement of an R&TTE Directive Notified Body for the final product. In all other cases, or if the manufacturer of the final product is in doubt then the equipment integrating the radio module must be assessed against Article 3.2 of the R&TTE Directive.”

ETSI Technical Report ETSI TR102 070-2, describes several applications of the above with different product configurations.

When the integration of a particular module does require assessment by a notified body, the technical documentation for the radio module will need to be reviewed by the NB, if not available, the NB may request this information from the radio module manufacturer. The NB may be unable to issue an opinion without this information. The integrator should ensure that the module manufacturer is willing to provide this information to the NB; however, the final Technical Construction File is not required to include the radio module manufacturer’s proprietary information. Furthermore, the final product integrator is cautioned to ensure that they know the build status of the integrated module.

The R&TTE guidance document also covers technical documentation, notification to national authorities, and marking requirements.

The full guidance document can be downloaded here

Be sure to visit for more information related to EU regulatory compliance.

UPDATE: part II available covering EMC considerations - 

Radio module integration and R&TTE compliance, EMC evaluation