BS PD ISO GUIDE 33:2015 describes good practice in using reference materials (RMs), and certified reference
materials (CRMs) in particular, in measurement processes. These uses include the assessment of precision
and trueness of measurement methods, quality control, assigning values to materials, calibration, and the
establishment of conventional scales. This Guide also relates key characteristics of various types of RMs
to the different applications.For CRMs, the metrological traceability of the property values to international scales or other
measurement standards has been established. For RMs not being CRMs, this kind of traceability of
property values has often not been established. Nevertheless, these RMs can still be used for assessing
parts of measurement procedures, including evaluating various levels of precisionMainstream applications of RM include precision control (Clause 8), bias assessment (Clause 9),
calibration (Clause 10), preparation of calibration RMs (Clause 11) and maintaining conventional
scales (Clause 12).NOTE Not all types of RMs can be used for all indicated purposes.The preparation of RMs for calibration is also part of the scope of ISO Guides 34[1] and 35[2]. The
treatment in this Guide is limited to the fundamentals of small-scale preparation of RMs and the value
assignment, as used by laboratories to calibrate their equipment. Larger scale production of such RMs,
with the possible aim of distribution is beyond the scope of this Guide. This type of activity is covered in
ISO Guides 34[1] and 35[2].The development of working standards, as used in, e.g. natural gas analysis, clinical chemistry,
and the pharmaceutical industry is not covered in this Guide. This type of activity is covered in ISO
Guides 34[1] and 35[2].Cross References:ISO 3534-1ISO Guide 30ISO/IEC Guide 98-3ISO/IEC Guide 99:2007ISO Guide 34ISO Guide 35ISO Guide 80ISO/IEC 17025ISO 15189NEN 7779:2008ISO 5725-1ISO 5725-2ISO 5725-3ISO 5725-4ISO 5725-5ISO 5725-6ISO 7870-5ISO 16269-4ISO Guide 31ISO 15194ISO 6143ISO 3534-1All current amendments available at time of purchase are included with the purchase of this document.