ISO 17025 specifies the general requirements for the competence to carry out calibrations, including sampling.
It is applicable to all organizations/laboratoriess performing tests or calibrations. These include laboratories where testing or calibration forms part of inspection and product certification.
ISO 17025 certification (aligned with ISO 9000) has grown steadily over recent years. Third party auditing of the laboratory for this is not usually carried out by a certification body but by the national organisation responsible for accreditation itself.