One important aspect of Legal Metrology (or “Weights and Measures”) is the verification of measuring instruments used for purposes under legal control, such as commercial transactions. Verification of an individual measuring instrument is generally only performed if the type of the instrument has been examined and a type approval certificate issued.
“Conformity to Type” (CTT) refers to the requirement that measuring instruments submitted for verification must be manufactured in conformity with the approved type. With today’s technologies, it is often very difficult, if not impossible, to check for CTT at verification.
Most Legal Metrology Authorities would have become aware of non-conforming instruments from time to time. Such instruments may be detected by accident, or as a result of a specific (national) program.
However, it is believed that a large number of non-conformities remain undetected at verification. We have all heard of the “gold plated” instrument that is fully tested by the manufacturer prior to submission for type approval, while production instruments may receive less attention and may, in fact, be non-conforming.
The OIML’s Mutual Acceptance Arrangement (MAA) operates at the level of type approval of measuring instruments. Test results obtained by a participating laboratory are accepted by other participants. Confidence is based on a peer review process. The OIML MAA is an important tool in establishing confidence that the type of a measuring instrument complies with the requirements (as laid down in the appropriate OIML Recommendation).
For many years, the OIML has discussed the issue of CTT, in ad-hoc working groups and in the CIML. At the 45th CIML Meeting (2010) a proposal to establish a new technical (sub)committee to deal with CTT was discussed. The CIML considered that before it could take a decision, more insight into the possible structures and objectives of an OIML CTT program would be necessary; it agreed that the options should be investigated in a CTT seminar.
The objective of the CTT seminar, therefore, is to investigate the possible options for an OIML CTT program and to formulate (alternative) proposals for consideration by the CIML at its 46th Meeting (Prague, October 2011).
The CIML meeting in Prague will be preceded by a seminar (on Monday, 10 October 2011) to discuss the outcome of the CTT seminar in Utrecht and to formulate draft resolutions for adoption by the CIML.
For further information please contact:
Willem Kool - Assistant Director
11 rue Turgot | F-75009 Paris | France
Email - Phone