Quality assurance requirements for the management of measuring and test equipment

It is suggested that all measurement standards and measuring equipment should be calibrated using measurement standards that are traceable to international measurement standards, or to national measurement standards that are consistent with the recommendations of the CGPM (General Conference on Weights and Measures). In cases where such national or international measurement standards do not exist (for example, for hardness), traceability should be established to other measurement standards (for example, industry standards) that are internationally accepted in the field concerned