BIPM Key Comparison Database for Measurement Quality
- 1. CMCs and the BIPM Key CMCs and the BIPM Key Comparison Database Comparison Database Raul Fernando Solís Betancur Raul Fernando Solís Betancur rsolis@cenamep.org.pa 2015 2015
- 2. CIPM MRA CIPM MRA • Is the International Committee for Weights and Measures Mutual Recognition Arrangement. • Is the framework through which National Metrology Institutes demonstrate the international equivalence of their measurement standards and the calibration and measurement certificates they issue. • The CMC is the final product of all work in the CIPM MRA. 02/06/25 2
- 3. Bureau International des Poids et Bureau International des Poids et Mesures Mesures • International organization that resides in Paris, France. • Coordinate the international metrology activities like comparisons, the units, the measurement capabilities, etc. • Keeps a database of all comparison, calibration and measurement capabilities and provides worldwide access to the results. 02/06/25 3
- 4. The BIPM Key Comparison Data The BIPM Key Comparison Data Base Base • Containing Appendices A, B, C and D of the CIPM MRA. • Appendix A: Participants in the CIPM MRA. • Appendix B: Key and supplementary comparisons. • Appendix C: Calibration and Measurement Capabilities – CMCs. • Appendix D: List of key comparisons. 02/06/25 4
- 5. Comparisons (I) Comparisons (I) • They are the best way to show the level of your measurement skill. • You need to participate in almost one comparison to validate yours capabilities and to include your CMC in the database. • Under the CIPM MRA, the comparison can be Key or supplementary. • The result are published in the Appendix B. 02/06/25 5
- 6. Comparison (II) Comparison (II) • CIPM Key Comparison – Comparison between NMIs with the highest level of skills in the measurement or the unit realization. – The result of the comparison is a reference value of the quantity. • MRO Key Comparison – Comparison between NMIs in a RMO when one or more of the participants are in a CIPM Key comparison. – Don’t change the reference value obtained in the CIPM Key comparison. 02/06/25 6
- 7. Comparison (III) Comparison (III) • Supplementary Comparison: Is the comparison that helps link the NMI capabilities with the reference values (bilateral, pilots experiments, etc.). • All of the participants of all comparison must be signatory of the MRA. • If one of the participants isn't a MRA signatory, the comparison is only valid if you don’t include his data in the comparison result. 02/06/25 7
- 9. Comparison (V) Comparison (V) • The Universal Time Coordinated is our reference value (Key comparison CCTF-K001.UTC, started since 1977 and still ongoing). • The Circular T is the official document that reports the key comparison results. • The UTCr is a rapid solution for the laboratories that seek to steer their definitions close to the UTC. 02/06/25 9
- 12. SIM comparisons (I) SIM comparisons (I) • The Time & Frequency Network is an pilot experiment that acts like a regional comparison. • SIMTFN is a method that allow bilateral comparison between the T&F Key Comparison participants and the rest of the laboratories. • The objective of this comparison is the increase of the calibration capabilities of all T&F laboratories in our region. • The results are published every hour in the SIMTF webpage. 02/06/25 12
- 13. SIM comparisons (II) SIM comparisons (II) 02/06/25 13
- 14. SIM comparisons (III) SIM comparisons (III) 02/06/25 14
- 15. Calibration and Measurement Calibration and Measurement Capability (I) Capability (I) • The MRA seeks to bring equivalence in all the measurements in the world. • The only way to ensure that this happens is to normalize our way to measure and express the results. • The Calibration and Measurement Capability (CMC) is the final product of these process. 02/06/25 15
- 16. Calibration and Measurement Calibration and Measurement Capability (II) Capability (II) • The BIPM has a list of CMC for the 9 metrology areas. • Every NMI that is part of the MRA and can provide enough evidence of their measurement skills in these areas can register their capabilities in the Appendix C. • The SIM region has only 6 laboratories with CMC in the T&F metrology area (approximately 45 in total around the world, December 2014). 02/06/25 16
- 17. Calibration and Measurement Calibration and Measurement Capability (III) Capability (III) • For the declaration of your CMC you need: • To be a signatory of the MRA (member or associate state). • A peer review in the service that you want to publish (is better if the evaluator is from other NMI with a CMC or a good reputation in the metrology area). • To fulfill the quality assessment under the ISO/IEC 17025. 02/06/25 17
- 18. Calibration and Measurement Calibration and Measurement Capability (IV) Capability (IV) • For the approval of your CMC you need: • A comparison with some NMI with link to the UTC. • The approval of your Quality System from the SIM QSTF. • The approval of your technical capabilities from all RMOs. • Fulfilling all these points grants the incorporation of your CMC in the Appendix C. 02/06/25 18
- 19. Calibration and Measurement Calibration and Measurement Capability (V) Capability (V) • The CMC only had a vitality of 5 years. After that you need to perform the same exercise to maintain yours CMC. • The values can be updated for better or for worse. – This depend of the actual situation in your laboratory (changes in your equipment, environmental condition, calibration methods, etc.). 02/06/25 19
- 20. Calibration and Measurement Calibration and Measurement Capability (VI) Capability (VI) • To demonstrate vitality you need to show record of your work by: • Comparisons. • Publications of your work (journals, conference proceedings, etc.). • Participation in the Working Groups. • Advisories / third party audits. • Trainings. • Continuous improvement through R&D. 02/06/25 20
- 21. Classification of services in Time Classification of services in Time and Frequency and Frequency • In the T&F metrology area, the measurement capabilities are divided in three branches (version 1.0 of December 2002): • Time scale difference: synchronization with UTC or UTC(k). • Frequency: frequency difference. • Time interval: duration of events. 02/06/25 21
- 22. Branch: 1 Branch: 1 Time scale difference Time scale difference • 1.1. Local clock • 1.1.1. Local clock vs. UTC(NMI) • 1.1.2. Local clock vs. UTC • 1.2. Remote clocks • 1.2.1. Remote clock vs. UTC(NMI) • 1.2.2. Remote clock vs. UTC 02/06/25 22
- 23. Branch: 2 Branch: 2 Frequency Frequency • 2.1. Standard frequency source • 2.1.1. Local frequency standard • 2.1.2. Remote frequency standard • 2.2. General frequency source • 2.2.1. General frequency source • 2.3. Frequency meter • 2.3.1. Frequency counter • 2.3.2. Frequency meter 02/06/25 23
- 24. Branch: 3 Branch: 3 Time interval (I) Time interval (I) • 3.1. Period source • 3.1.1. Period source • 3.2 Time Interval source • 3.2.1. Rise/fall time source • 3.2.2. Pulse width source • 3.2.3. Time difference source • 3.2.4. Delay source 02/06/25 24
- 25. Branch: 3 Branch: 3 Time interval (II) Time interval (II) • 3.3. Period meter • 3.3.1. Period meter • 3.4 Time Interval meter • 3.4.1. Rise/fall time meter • 3.4.2. Pulse width meter • 3.4.3. Time difference meter • 3.4.4. Delay meter 02/06/25 25
- 26. The CMC sheet (I) The CMC sheet (I) 02/06/25 26
- 27. The CMC sheet (II) The CMC sheet (II) 02/06/25 27
- 28. Calibration or Measurement Calibration or Measurement Service Service Calibration or Measurement Service Quantity/ Class Instrument or Artifact Instrument Type or Method 02/06/25 28
- 29. Calibration or Measurement Calibration or Measurement Service Service • Quantity / Class: basically the branch that you want to measure (frequency, time interval or time scale difference). • Instrument or Artifact: Is the device under test but in terms of the sub points of the branch (1.x., 2.x., 3.x., 1.x.x., 2.x.x and 3.x.x.). • Instrument Type or Method: How you perform the comparison or the data acquisition (direct frequency measurement, direct comparison against UTC(k), etc). 02/06/25 29
- 30. Measurement Level or Range Measurement Level or Range Measurand Level or Range Minimum value Maximum value Units 02/06/25 30
- 31. Measurement Level or Range Measurement Level or Range • Minimum Value: the lower number that you can acquire in your measurement range. • Maximum value: the highest number that you can acquire in you measurement range. • Units: the units of the values that you acquire. 02/06/25 31
- 32. Measurement Measurement Conditions/Independent Variable Conditions/Independent Variable Measurement Conditions/Independent Variable Parameter Specifications 02/06/25 32
- 33. Measurement Measurement Conditions/Independent Variable Conditions/Independent Variable • Parameter: every variable or condition that limit your measurement capability (gate time, measurement time, averaging time, signal amplitude, line impedance, slew rate, etc.). • Specification: the limits of the parameters in yours measurement. 02/06/25 33
- 34. Expanded Uncertainty Expanded Uncertainty Expanded Uncertainty Value Units Coverage Factor Level of Confidence Is the expanded uncertainty a relative one? 02/06/25 34
- 35. Expanded Uncertainty Expanded Uncertainty • Value: the uncertainty’s value that you want to declare. • Units: the units of your declared uncertainty. • Coverage factor: the value that you use to expand your standard uncertainty (usually k=2). • Level of Confidence: usually is 95%. • Is the expanded uncertainty a relative one?: Indicates if the value of uncertainty has turned relative. 02/06/25 35
- 36. Reference Standard used in Reference Standard used in calibration calibration Reference Standard used in calibration Standard Source of traceability 02/06/25 36
- 37. Reference Standard used in Reference Standard used in calibration calibration • Standard: your time and frequency reference. • Source of Traceability: The INM is the one that has traceability to the time unit. 02/06/25 37
- 38. List of Comparisons supporting this List of Comparisons supporting this measurement/calibration service measurement/calibration service List of Comparisons supporting this measurement / calibration service 02/06/25 38
- 39. List of Comparisons supporting this List of Comparisons supporting this measurement/calibration service measurement/calibration service • List of Comparisons supporting this measurement / calibration service: The comparison that you have participated in to show your measurement capabilities to another NMI. 02/06/25 39
- 40. Comments to be published via the Comments to be published via the web page web page Comments to be published via the web page 02/06/25 40
- 41. Comments to be published via the Comments to be published via the web page web page • Comments to be published via the web page: information about the calibration, uncertainty, and when the CMC is published. 02/06/25 41
- 43. Administration Administration • NMI Service Identifier: The internal ID for the NMI to identify this service. • Service Category: The CMC service identifier. • NMI: The National Metrology Institute or delegated metrology institute that publishes the CMC. • Review Status: the actual situation of the verification of your CMC. • Review Comments: aditional information about the verification process. 02/06/25 43
- 44. Example of filling a CMC Sheet Example of filling a CMC Sheet 02/06/25 44
- 45. Example of filling a CMC Sheet Example of filling a CMC Sheet 02/06/25 45
- 46. How the world see your CMC How the world see your CMC 02/06/25 46
- 47. Discussion Discussion • What is the individual need of the NMI to register your CMC in the KCDB?. • The need for training and technical advising. • You can start with a low level capability calibration services like stopwatches, frequency meters or optical tachometers (rubidium oscillator is enough for this). • Do you need to increase your measurement capability confidence? Do you need a pilot comparison? • Tell us what you think. 02/06/25 47
- 48. Useful links Useful links • SIM TFWG page: http://tf.nist.gov/sim/ • BIPM KCDB page: http://kcdb.bipm.org/ • CIPM MRA page: http://www.bipm.org/en/cipm-mra/ • BIPM T&F server page: http://www.bipm.org/en/bipm-services/timescales/time-ftp.htm l • NIST uncertainty of measurements result page: http://physics.nist.gov/cuu/Uncertainty/index.html 02/06/25 48