TY - JOUR A1 - Örnemark, U. A1 - Fostel, H. A1 - Straub, R. A1 - van de Kreeke, Johannes T1 - Policies, requirements and surveys concerning frequency for participation in proficiency testing schemes JF - Accreditation and quality assurance N2 - This paper focuses on policies and requirements concerning the frequency for participation in proficiency testing (PT) and provides an overview of the frequency for which PT activities are offered in 25 testing fields. Recent international surveys are summarised. KW - Proficiency testing KW - External quality assessment KW - Frequency KW - Accreditation KW - Policy documents KW - Eptis PY - 2004 DO - https://doi.org/10.1007/s00769-004-0858-2 SN - 0949-1775 SN - 1432-0517 IS - 9 SP - 729 EP - 732 PB - Springer CY - Berlin AN - OPUS4-5198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -