metrological traceability policy

DAkkS adjusts its requirements regarding the metrological traceability policy

Requirement of the European Cooperation for Accreditation
Technical Information,

The so-called „metrological traceability” is one of the pillars of conformity assessment. The German national accreditation body (DAkkS) has adjusted its requirements regarding the metrological traceability policy in order to meet the requirement of the European Cooperation for Accreditation (EA). As of August 2016 the acceptance of verification reports issued by German verification authorities (“Eichbehörden”) as evidence of metrological traceability will only be possible in individual cases.

Whenever measurements are carried out and conformity assessment is based on measurement results, the metrological traceability is of utmost importance. In this way, laboratories and inspection bodies ensure the “correctness” of the measurements and conclusions based on it – like compliance with threshold values. In the accreditation process, these bodies must prove, that the traceability of their measurement instruments conform to international requirements.

The metrological requirements are laid down in the international standard ISO/IEC 17025:2005 of the International standard Organization (ISO) and the binding requirements of the accreditation document ILAC P10:2013, issued by the International Laboratory Accreditation Cooperation (ILAC). For all conformity assessment bodies accredited by DAkkS these requirements are outlined in the DAkkS document “Technical Note for the Metrological Traceability in the Accreditation Process” (71 SD 0 005). This document had to be adapted in particular with regard to the role of the German verification bodies.

In which cases verification reports issued by German verification bodies are at present accepted?

The DAkkS document lists concrete possibilities how conformity assessment bodies can prove towards DAkkS the fulfillment of metrological traceability. One possibility consisted in presenting a report of German verification authorities, which had passed successfully an assessment by PTB regarding the metrological traceability for the relevant measurement parameter. This approach has been considered by DAkkS, by the responsible Ministry for Economic Affairs and Energy (BMWi) and by accredited conformity assessment bodies as to be a possible route to prove metrological traceability.

Why will this current practice change?

During the peer evaluation of DAkkS in autumn 2014, the European Cooperation for Accreditation (EA) has objected to the acceptance -under certain conditions- of reports issued by verification authorities as proof of metrological traceability, as evidence of metrological traceability without further assessment by the accreditation body is only possible when the body issuing this evidence is accredited. According to international rules (ISO/IEC 17025:2005) an assessment by PTB only is not sufficient. In October 2015 DAkkS has been ultimately requested by EA to change its policy in this regard.

After lodging an appeal, EA confirmed once more its opinion on 28 January 2016. Because of this EA decision DAkkS - in agreement with BMWi and PTB - modified the technical note 71 SD 0 005 and published its revision 1.4 on 1 February 2016.

How does the metrological traceability change?

The conditions for traceability regarding „ Reports without the accreditation symbol” in clause 6 of the technical note have been newly formulated. Clause 6.c) “Reports without accreditation symbol issued by the German verification authorities” has been deleted. Hence reports issued by the German verification authorities are treated like reports without accreditation symbol issued by non-accredited bodies.

The acceptance of verification certificates issued by these authorities as evidence of metrological traceability is only possible in individual cases. The necessary assessment of the bodies that issue certificates (evidence of metrological traceability) is to be conducted by DAkkS only.

Another restriction concerns reports without accreditation symbol issued by accredited calibration laboratories for calibrations covered exactly by their accreditation scope. These reports will no longer be accepted as evidence of metrological traceability as they are not subject to the surveillance activities within the accreditation process. According to clause 6.b of the technical note also for these reports, the competence of the issuing body for the specific calibration must be proven in individual cases.

How the transition takes place and what does DAkkS suggest?

The revision 1.4 of the technical note 71 SD 0 005 enters into force six months after its publication on 1. August 2016. Until then forms of evidence for metrological traceability conforming to the previous requirements continue to be valid. As of August 2016 all forms of evidence for metrological traceability provided within the context of DAkkS’ assessment must meet the requirements of the revised technical note.

DAkkS suggests to conformity assessment body to use the transitional period to verify their evidence for metrological traceability and eventually to adapt them to the new requirements. The accreditation body suggests providing forms of evidence as described in section 1 – 5. The assessment effort by DAkkS is in these cases are comparatively low.

Traceability according to clause 6 of the technical note can only be taken into consideration, when route 1-5 are not possible. Should the evidence still be provided according to route 6, the accredited body must ensure that all conditions – for example access rights- are given, so that the assessment of the metrological traceability of the issuing body can be carried out as well. This entails a major assessment effort by DAkkS, leading possibly to delays and significant additional costs for the conformity assessment body.

As far as conformity assessment have recourse to services of calibration laboratories, they should ensure that these bodies are accredited for the needed calibration. This can be verified by checking the directory of accredited bodies published on the DAkkS webpage.

What does it mean for the metrological traceability for general inspections and exhaust emissions test?

The revised traceability policy according to the EA requirements fully applies to inspections and exhaust emissions tests carried out according to the national type-approval regulation by surveillance organizations in the frame of their accreditation.

Further details – like the implementation of transitional provisions- are communicated by DAkkS via an information letter to all accredited conformity assessment bodies in February 2016.

Dr. Heike Manke

Head od Division Metrology | Construction | Transport | Renewable Energy

Go back

Nach oben