CMCs and the BIPM Key Comparison Database Raul Fernando Solís Betancur 2015

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. 6/9/20152

Bureau International des Poids et 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. 6/9/20153

The BIPM Key Comparison Data 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. 6/9/20154

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. 6/9/20155

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. 6/9/20156

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. 6/9/20157

Comparison (IV) 6/9/20158

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. 6/9/20159

Circular T 6/9/201510

UTCr results 6/9/201511

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. 6/9/201512

SIM comparisons (II) 6/9/201513

SIM comparisons (III) 6/9/201514

Calibration and Measurement 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. 6/9/201515

Calibration and Measurement 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). 6/9/201516

Calibration and Measurement 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 /9/201517

Calibration and Measurement 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. 6/9/201518

Calibration and Measurement 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.). 6/9/201519

Calibration and Measurement 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. 6/9/201520

Classification of services in Time 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. 6/9/201521

Branch: 1 Time scale difference 1.1. Local clock Local clock vs. UTC(NMI) Local clock vs. UTC 1.2. Remote clocks Remote clock vs. UTC(NMI) Remote clock vs. UTC 6/9/201522

Branch: 2 Frequency 2.1. Standard frequency source Local frequency standard Remote frequency standard 2.2. General frequency source General frequency source 2.3. Frequency meter Frequency counter Frequency meter 6/9/201523

Branch: 3 Time interval (I) 3.1. Period source Period source 3.2 Time Interval source Rise/fall time source Pulse width source Time difference source Delay source 6/9/201524

Branch: 3 Time interval (II) 3.3. Period meter Period meter 3.4 Time Interval meter Rise/fall time meter Pulse width meter Time difference meter Delay meter 6/9/201525

The CMC sheet (I) 6/9/201526

The CMC sheet (II) 6/9/201527

Calibration or Measurement Service Quantity/ Class Instrument or Artifact Instrument Type or Method 6/9/201528

Calibration or Measurement 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). 6/9/201529

Measurement Level or Range Measurand Level or Range Minimum value Maximum value Units 6/9/201530

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. 6/9/201531

Measurement Conditions/Independent Variable ParameterSpecifications 6/9/201532

Measurement 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. 6/9/201533

Expanded Uncertainty ValueUnits Coverage Factor Level of Confidence Is the expanded uncertainty a relative one? 6/9/201534

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. 6/9/201535

Reference Standard used in calibration Standard Source of traceability 6/9/201536

Reference Standard used in calibration Standard: your time and frequency reference. Source of Traceability: The INM is the one that has traceability to the time unit. 6/9/201537

List of Comparisons supporting this measurement/calibration service 6/9/201538

List of Comparisons supporting this 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. 6/9/201539

Comments to be published via the web page 6/9/201540

Comments to be published via the web page Comments to be published via the web page: information about the calibration, uncertainty, and when the CMC is published. 6/9/201541

Administration Administration NMI Service Identifier Service Category NMI Review Status Review Comments 6/9/201542

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. 6/9/201543

Example of filling a CMC Sheet 6/9/201544

Example of filling a CMC Sheet 6/9/201545

How the world see your CMC 6/9/201546

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. 6/9/201547

Useful links SIM TFWG page: BIPM KCDB page: CIPM MRA page: BIPM T&F server page: services/timescales/time-ftp.htmlhttp:// services/timescales/time-ftp.html NIST uncertainty of measurements result page: 6/9/201548

¡Thanks! 6/9/201549