Membership of a Consultative Committee is open to institutions of Member States of the Metre Convention that fulfil the following criteria.

Laboratories invited to be members of a Consultative Committee are those already recognized internationally as most expert in the field. This normally requires that they:

• be national laboratories charged with establishing national standards in the field;
• be active in research and have a record of publications in research journals of international repute;
• have demonstrated competence by a record of participation in international comparisons organized either by the Consultative Committee, the BIPM or a regional metrology organization.

In addition to laboratory members, Consultative Committees may include as members:

• named individuals whose knowledge and competence in the field are such that they can provide valuable assistance to the Consultative Committee even though they do not come from a laboratory meeting the requirements for membership;
• international unions or other international organizations whose advice or expertise would be helpful to the Consultative Committee.

The Presidents of Consultative Committees may from time to time invite observers to meetings, including representatives of appropriate laboratories that are not yet members.

In general, the national metrology institute of each Member State of the Metre Convention wishing to participate can expect to be a member or an observer of at least one Consultative Committee.

Applications should be sent to the Director of the BIPM or to the President of the Consultative Committee.