Principles of the OIML-CS

The OIML-CS is a system for issuing, registering and using OIML certificates, and their associated OIML type evaluation/test reports, for measuring instruments based on the requirements of OIML Recommendations

The aim of the OIML-CS is to facilitate, accelerate and harmonize the work of national and regional bodies that are responsible for type evaluation and approval of measuring instruments subject to legal metrological control.

In the same way, instrument manufacturers, who are required to obtain type approval in some countries in which they wish to sell their products, should benefit from the OIML-CS as it will provide evidence that their instrument type complies with the requirements of the relevant OIML Recommendation(s).

It is a voluntary system and OIML Member States and Corresponding Members are free to participate. Participating in the OIML-CS and signing a Declaration will commit, in principle, the signatories to abide by the rules of the OIML-CS.

OIML B 18:2022 establishes these rules whereby signatories voluntarily accept and utilize OIML type evaluation and test reports, when associated with an OIML-CS certificate issued by an OIML Issuing Authority, for type approval or recognition in their national or regional metrological controls.

Objectives of the OIML-CS

The objectives of the OIML-CS are

to promote the global harmonization, uniform interpretation and implementation of legal metrological requirements for measuring instruments and/or modules,
to avoid unnecessary re-testing when obtaining national type evaluations and approvals, and to support the recognition of measuring instruments and/or modules under legal metrological control, while achieving and maintaining confidence in the results in support of facilitating the global trade of individual instruments, and
to establish rules and procedures for fostering mutual confidence among participating OIML Member States and Corresponding Members in the results of type evaluations that indicate conformity of measuring instruments and/or modules, under legal metrological control, to the metrological and technical requirements established in the applicable OIML Recommendation(s).

Benefits of the OIML-CS

The various stakeholders may benefit from the OIML-CS:

for national legal metrology authorities from countries in which no test facilities are available and where national type evaluations and approvals are required, the OIML-CS offers a viable solution;
for instrument manufacturers who are required to obtain type approval, the OIML-CS may provide evidence that their instrument type complies with the requirements of the relevant OIML Recommendations, thus avoiding duplication of type approval tests in different countries; and
the OIML-CS additionally provides formal evidence to accept and utilize OIML Type Evaluation Reports validated by an OIML Certificate of Conformity.

Scope and participation

There are three categories of participants:

OIML Issuing Authorities are conformity assessment bodies from OIML Member States that issue OIML Certificates and associated OIML type evaluation reports in accordance with Scheme A or Scheme B.
Utilizers are national issuing authorities or national responsible bodies from OIML Member States that utilize and accept OIML Certificates and/or OIML type evaluation reports issued under Scheme A or Scheme B as the basis for issuing a national or regional type approval.
Associates are national issuing authorities or national responsible bodies from OIML Corresponding Members that utilize and accept OIML Certificates and/or OIML type evaluation reports issued under Scheme A or Scheme B as the basis for issuing a national or regional type approval. Associates do not have voting rights in the Management Committee.

Those categories of measuring instruments (including families of instruments, modules, or families of modules) for which the relevant OIML Recommendation specifies the metrological and technical requirements, the test procedures, and the OIML test report format are automatically included in the OIML-CS. A category of measuring instrument is initially placed in Scheme B, with the intention that all categories of measuring instruments in the OIML-CS will transition to Scheme A two years after first being included in the OIML-CS.

The requirements for the participation of OIML Issuing Authorities and their associated Test Laboratories in Scheme A or Scheme B are the same, but the method of demonstrating compliance is different. OIML Issuing Authorities are required to demonstrate compliance with ISO/IEC 17065 or ISO/IEC 17020 (with additional requirements), and Test Laboratories are required to demonstrate compliance with ISO/IEC 17025. For participation in Scheme B, it is sufficient to demonstrate compliance on the basis of “self-declaration” with additional supporting evidence. However, for participation in Scheme A, compliance shall be demonstrated by peer evaluation on the basis of accreditation or peer assessment.

Further information

Further information on the OIML-CS can be found in OIML Publication B 18 Framework for the OIML Certification System (OIML-CS). Detailed information regarding the operating rules and procedures can be found in the Operational Documents and Procedural Documents. Various Templates, Forms and Guides have been developed to assist the users of the system.

An animated video "Introduction to the OIML Certifications System (OIML-CS) was uploaded to the OIML YouTube channel on 2023-09-29.

Home