1. 2006 NCSL International Workshop and Symposium August 07 Management of the AC-DC voltage transfer difference comparison in the SIM region Sara Campos CENAM - Mexico Electromagnetic Measurement Division - Electrical Metrology

2. 2006 NCSL International Workshop and Symposium August 07 Contents Introduction Planning of the comparison Technical Protocol Circulation of the traveling standard Actual state of the comparison

3. 2006 NCSL International Workshop and Symposium August 07 http://www.sim-metrologia.org.br/whoweare/sm_whoweare.html NRC NIST CENAM INMETRO UTE INTI NMI´s in the SIM region with CMC´s on ac-dc transfer difference, with entries in the Appendix C of the CIPM MRA

4. 2006 NCSL International Workshop and Symposium August 07 http://www.sim-metrologia.org.br/whoweare/sm_whoweare.html NRC NIST INTI NMI´s in the SIM region with participation in the CIPM key comparisons, on ac-dc voltage transfer difference (e.g. CCEM-K6a, CCEM-K9, CCEM-K11)

5. 2006 NCSL International Workshop and Symposium August 07 A regional comparison was planned with the main goals: Strengthen the interaction among NMI´s in the SIM region with CMC´s on ac-dc voltage transfer difference. According to the MRA objectives: Establish the degree of equivalence of national measurement standards, on ac-dc voltage transfer difference, maintained by NMI´s in the SIM region.

6. 2006 NCSL International Workshop and Symposium August 07 CENAM volunteered to be the pilot laboratory and the provider of the traveling standard Proposals: Measurement points and participants Proposal of a Regional Key Comparison: Pilot laboratory responsible for draw up the technical protocol. 2003: Technical protocol sent for review to the participants. 2002: Technical protocol reviewed by: WGLF and the CCEM SIM.EM-K6a, SIM.EM-K9 and SIM.EM-K11, 120 V/53 Hz. Technical protocol and comparison approved Starting date: January 2004.

7. 2006 NCSL International Workshop and Symposium August 07 Traveling Standard description : Definition of the measurand:  = (Vac - Vdc) / Vdc Technical protocol List of participants and Timetable Clearing customs Measuring 14 points Shipping to the next laboratory 6 weeks were establish for: Procedure in case of failure or unexpected delay A commercial ac-dc transfer standard Good stability known. (Registers from the pilot laboratory since1996)

8. 2006 NCSL International Workshop and Symposium August 07 Transport and Customs - Letter describing the traveling standard and the purpose of its travel. - South America customs: Hand carried. - Use of a recognized shipment service for transportation. Financial aspects Organization of the American States (OAS ) afforded flight tickets Mexico-Argentina-Mexico Uruguay-Brazil-Uruguay Brazil-Mexico-Argentina Transportation cost was on each laboratory’s responsibility

9. 2006 NCSL International Workshop and Symposium August 07 Reporting the results (when and how) Appendix: Format to report the results Measurement points

10. 2006 NCSL International Workshop and Symposium August 07 Determination of the reference value values from laboratories in SIM who took part in the CCEM-K6a, CCEM-K9 and CCEM-K11 key comparisons. Degree of equivalence and its uncertainty D i =  i -  SIM-ref.value

11. 2006 NCSL International Workshop and Symposium August 07 Degree of equivalence between pairs and its uncertainty PTB - Germany INTI, INMETRO, UTE, CENAM Correlation expected Link with CCEM key comparison Final report Reymann D., Link between the comparison EUROMET.EM.BIPM-K11.b and the ongoing comparison BIPM.EM-K11.b, Metrologia, 2003, 40, Tech. Suppl., 01005 Responsible for draw up Draft A: Pilot laboratory

12. 2006 NCSL International Workshop and Symposium August 07 Circulation of the traveling standard

13. 2006 NCSL International Workshop and Symposium August 07 Draft A of the Report Reports were received during 2004 - 2005. Draft A of the report was send for review to the participant at the beginning of 2006 The pilot laboratory received comments asking for including: -information of the stability of the traveling standard -degrees of freedom And: -Giving guidelines to evaluate in a rigorous way the correlation.

14. 2006 NCSL International Workshop and Symposium August 07 1.Organize and pilot a comparison is a hard work. 2.Guidelines for key comparison issued by the CIPM helps to focus the attention on the technical work. 3.Challenge: deep statistical analysis. However, thanks to the experiences of others RMOs, many technical references could be consulted. 4.Experiences acquired in conducting a comparison. Conclusions:

15. 2006 NCSL International Workshop and Symposium August 07 Acknowledges: The participants: Technical committee of the SIM: - Harold Sanchez - Luis Mussio - Yoshito Mitani - Peter Filipski (NRC Canada) - Joseph Kinard and Thomas Lipe (NIST USA) - Héctor Laiz and Lucas Di Lillo (INTI Argentina) - Alfredo Spaggiari (UTE Uruguay) - Edson Afonso and Giovanna Borghi (INMETRO Brazil) - CENAM staff

16. 2006 NCSL International Workshop and Symposium August 07 Thank you for your attention