1. Traceability to the SI: What does it mean in practice? Ms. Sally Bruce and Ms. Dana Leaman National Voluntary Laboratory Accreditation Program NIST

2. Reference Information –ISO/IEC 17025:2005, Section 5.6 Measurement Traceability –JCGM 200:2008 – International vocabulary of metrology – Basic and general concepts and associated terms (VIM) –NIST Traceability Policy –ILAC P10:2002 – ILAC Policy on Traceability of Measurement Results –NIST Handbook 150:2006 – Procedures and General Requirements: Annex B, Implementation of traceability policy in accredited laboratories 2

3. ISO/IEC 17025:2005 Clause 5.6.2 Measurement Traceability 5.6.2.1 “For calibration laboratories, the program for calibration of equipment shall be designed and operated so as to ensure that calibrations and measurements made by the laboratory are traceable to the International System of Units(SI) (Système international d’unités).” 3

4. Defining Traceability 4 The definition for a metrology laboratory: VIM3: The property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty.

5. NIST Policy on Traceability NIST Traceability Policy –Supplementary Materials – Resource on FAQs regarding traceabilitySupplementary Materials 5

6. SI Base Units Base QuantityNameSymbol Lengthmeterm Masskilogramkg Timeseconds Electric CurrentampereA Thermodynamic Temperature kelvinK Luminous IntensitycandelaCd Amount of Substance molemol 6

7. The SI Brochure 7 http://www.bipm.org /en/si/si_brochurehttp://www.bipm.org /en/si/si_brochure/

8. The Traceability Chain: Mass 8 The sequence of measurement standards and calibrations that is used to relate a measurement result to a reference. The farther your measurements are down in the traceability chain, the higher the uncertainty of the measurement. Figure courtesy of the BIPM website

9. Benefits of Traceability Essential requirement of a quality management system for calibration laboratories Means to Ensure Accuracy Competiveness and Operation in a Global environment – Facilitation of Trade A concept in the standardization of measurements 9

10. Understanding the International BIG Picture 10 Copyright Robert Rathe Photo courtesy of BIPM Realization of the SI in each Country or Economy The National Institute of Standards and Technology is the National Metrology Institute in the United States

11. Understanding the International BIG Picture 11 The CIPM MRA (Mutual Recognition Arrangement of the International Committee of Weights and Measures) creates a framework for the NMIs*. All the laboratories that meet the requirements of the MRA have agreed to recognize the Calibration and Measurement Capabilities and national measurement standards of the other participants. *currently 86 Institutes have signed the CIPM MRA additionally it covers 137 designated institutes

12. Mutual Recognition Arrangements for Accreditation Bodies ILACAPLACNVLAPA2LAACLASSIASLABPJLAEAIAAC 12 International Laboratory Accreditation Cooperation (ILAC) AB’s in the US that are signatories to the ILAC MRA* Regional Accreditation Cooperations *Currently 88 economies are represented in the ILAC network; ~35,000 laboratories are accredited world-wide by ILAC signatories

13. ILAC P10:2002 Section 1.4: Characteristics of traceability –Unbroken chain of comparisons –Uncertainty of measurement –Documentation of the chain –Competence of the calibration provider –Reference to SI units –Calibration intervals 13

14. ILAC P10:2002 Section 2: ILAC Policy on Traceability of Measurement Results –Accredited labs shall demonstrate calibration of measurements are traceable to SI units –Accredited labs shall in all cases derive their traceability either: Appropriate NMI; or Calibration Lab that can demonstrate competence, measurement capability, and traceability with appropriate measurement uncertainty –Labs holding management certification not deemed acceptable as demonstrating necessary competence 14

15. Accreditation Body (AB) Requirements Each AB will have a policy Common Characteristics of each policy –Use of a National Metrology Institute (NMI) that is signatory to the CIPM MRA –Use of accredited calibration laboratory accredited by Mutual Recognition Arrangement (MRA) partner under ILAC 15

16. Is my measurement traceable? What must you know to prove your measurement is the result of an unbroken chain of calibrations? Does that chain of calibrations lead back to the SI unit realized by the NMI? How do you know? Is a statement of traceability on a calibration certificate enough? 16

17. Why should we be concerned? Greater awareness of the importance of measurement in all areas of science and technology. Understanding the fundamental basis that metrology plays. Focused attention on its impact. 17

18. Benefits of Traceability Competiveness and Operation in a Global environment – Trade Means to Guarantee Accuracy Essential part of a quality management system Link in the chain of techniques and measurements in a large, diverse measurement community 18

19. Reference Information Acronyms: AB – Accreditation Body APLAC – Asia Pacific Laboratory Accreditation Cooperation BIPM – Bureau International des Poids & Mesures CIPM – International Committee for Weights and Measures (Comité International des Poids et Mesures) CGPM – General Conference on Weights and Measures (Conférence Générale des Poids et Mesures) EA – European Co-Operation for Accreditation IAAC – Inter American Accreditation Cooperation ILAC – International Laboratory Accreditation Cooperation 19

20. Reference Information Acronyms: continued JCGM – Joint Committee for Guides in Metrology (Comité commun pour les guides en métrologie) KCDB – Key Comparison Database MRA – Mutual Recognition Arrangement NIST – National Institute of Standards and Technology NMI – National Metrology Institute SI – International System of Units VIM – International Vocabulary of Metrology 20

21. Reference Information Acronyms: continued U.S. Accreditation Bodies that issue scopes of accreditation to Calibration Laboratories - A2LA: American Association for Laboratory Accreditation ACLASS: Assured Calibration and Laboratory Accreditation Select Services IAS: International Accreditation Service, Inc. L-A-B: Laboratory Accreditation Bureau NVLAP: National Voluntary Laboratory Accreditation Program PJLA: Perry Johnson Laboratory Accreditation, Inc. 21

22. Reference Information Publications: APLAC PR008 International Recognition of Test, Calibration and Inspection Reports, Issue No. 38, 2009. BIPM International System of Units, 8th edition, 2006. ILAC P8:07 ILAC Mutual Recognition Arrangement(Arrangement): Supplementary Requirements and Guidelines for the Use of Accreditation Symbols and for Claims of Accreditation Status by Accredited Laboratories, 2006. ILAC P10 ILAC Policy on Traceability of Measurement Results, 2002. ISO 17025 General Requirements for the Competence of Testing and Calibration Laboratories, 2nd edition, 2005. JCGM 200 International Vocabulary of metrology – Basic and general concepts and associated terms (VIM), 2008. NIST Handbook 150 Procedures and General Requirements, 2006 edition. NIST Special Publication 330 The International System of Units (SI), 2008 edition. NIST Special Publication 811 Guide for the Use of International System of Units (SI), 2008 edition. 22

23. Reference Information Websites: APLAC – www.aplac.orgwww.aplac.org BIPM – www.bipm.orgwww.bipm.org EA – www.european- accreditation.orgwww.european- accreditation.org IAAC – www.iaac.org.mxwww.iaac.org.mx ILAC – www.ilac.orgwww.ilac.org NIST – www.nist.govwww.nist.gov NVLAP – www.nist.gov/nvlapwww.nist.gov/nvlap 23