1. APLAC Interlaboratry Comparison Program for Short Gauge Blocks - APLAC M018 Takashi Horaguchi International Accreditation Japan (IAJapn), National Institute of Technology and Evaluation (NITE)

2. Contents 1. Introduction of the APLAC ILC Program 2. Feature of the Program 3. Examination of the Results 4. Conclusion

3. Introduction of the APLAC ILC Programs Asia Pacific Laboratory Accreditation Cooperation (APLAC) Interlaboratory Comparisons (ILCs) Name of ILCOrganizing AB M001 Dimensional Metrology NATA M002 MassNATA M003 ResistanceTAF M019 Pressure MeterKOLAS M020 DC Current Measurement SM M021 VolumeKAN Calibration Name of ILCOrganizing AB T001 Metals in WaterNATA T002 TensileNATA T003 Dust in AirTAF T004 Food AdditivesHKAS T058 Malachite Green in Swamp Eels HKAS T059 Pesticide Residues in Ginseng Root HKAS Testing

4. Introduction of the APLAC ILC Programs Purpose of the APLAC ILCs  equivalence of measurement results  confidence in the accreditation process  corrective action  exchanging know-how  verification of measurement traceability

5. Introduction of the APLAC ILC Programs Participants ： APLAC members Extension of participation Participants ： APLAC, EA, IAAC members & accreditation bodies in the other regions Global Confidence

6. Feature of the Program Overview of APLAC M018  Name of ILC: APLAC Interlaboratory Comparison Program for Short Gauge Blocks-APLAC M018  Organizing Accreditation Body (AB): IAJapan  Period: from Oct. 2004 to Dec. 2007  Technical adviser: Dr. Hirokazu Matsumoto (NMIJ)  Measurement Method: Gauge Block (GB) Calibration  Participating AB: members of APLAC, EA, IAAC, and unaffiliated ABs

7. Feature of the Program Measurement Methods Interferometry method Comparison method Refer to ISO 3650 (JIS B 7506:2004) Gauge Block Wavelength of Light Measure Standard Gauge Block Gauge Block Compare

8. Feature of the Program Specifications of Artifacts GBs for Interferometry method Nominal Length: 1 mm, 8 mm, 75 mm (1 set) Grade: Grade K (JIS B7506:2004) Material: Steel Manufacturer: Tsugami Precision Co ltd GBs for Comparison method Nominal Length: 1 mm, 10 mm, 100 mm (5 sets) Grade: Grade 0 (JIS B7506:2004) Material: Steel Manufacturer: Mitutoyo Corporation Measuring face

9. Feature of the Program * * * Reference Laboratories * * * for Interferometry method National Metrology Institute of Japan (NMIJ) (signatory of CIPM MRA) for Comparison method Miyazaki Manufacturing Department, Hiroshima Operations, Mitutoyo Corporation (accredited by IAJapan since 1994)

10. Feature of the Program *The number in parenthesis is that of participating laboratories for interferometry method. Regional Cooperation Number of ABNumber of participant labs* APLAC2159(6) EA 514(2) IAAC 48 Others 15 Total3186(8) Participating ABs & Labs

11. Feature of the Program Artifacts Circulation Groups Interferometry method: 1 group (8 laboratories from 7 ABs) Comparison method: 5 groups (78 laboratories from 30 ABs)

12. Examination of the Results Evaluation Method: Measured data were evaluated with En number specified in the Appendix A of ISO/IEC Guide 43-1:1997. x lab : participant’s data X ref : Reference value U lab : Uncertainty of participant’s U ref : Uncertainty of reference Lab Satisfactory Result

13. Examination of the Results Interferometry method group Satisfactory: 6 labs Unsatisfactory: 1 lab Comparison method group Satisfactory: 62 labs (80 %) Unsatisfactory: 16 labs (20 %)

14. Examination of the Results Nominal length Participants data -Reference value (nm )Number of lab. Number of accepted lab. medianmaximumminimum 1 mm 9 56 -976 8 mm -17 42-2676 75 mm -21 9-3177 Deviations of Participants’ Data from Reference Values Interferometry method Nominal length Participants data -Reference value (nm)Number of lab. Number of accepted lab. medianmaximumminimum 1 mm 4 986-3447873 10 mm 10 1025-1087871 100 mm 32 382-3987767 Comparison method

15. Examination of the Results Nominal length Expanded uncertainty of participants (nm) medianmaximumminimum 1 mm304020 8 mm304020 75 mm407040 Interferometry method Nominal length Expanded uncertainty of participants (nm) medianmaximumminimum 1 mm7275030 10 mm8075030 100 mm16175050 Comparison method Measurement Uncertainty

16. Examination of the Results Deviations of Participants’ Data from Reference Values

17. Examination of the Results Measurement Uncertainty

18. Examination of the Results Deference Among Regions –Deviation of Participants’ Data from Reference Values (Comparison method) Nominal length (Participants data –Reference value) unit: nm APLACEAIAAC 1 mm 1(26) -6(39) 1(32) 10 mm10(37) 20(39) -5(44) 100 mm43(87) -23(104) -3(51) *The number inside the parenthesis is the standard deviation. no significant difference is observed

19. Examination of the Results Deference Among Regions – Median of Expanded Uncertainty (Comparison method) Nominal length Expanded Uncertainty of Participants (nm) APLACEAIAAC 1 mm 70(44)70(9) 80(19) 10 mm 80(43)72(7) 85(11) 100 mm161(63)155(59)135(30) *The number inside the parenthesis is the standard deviation. no significant difference is observed

20. Examination of the Results Same ratio of satisfactory results!! Deference Among Regions – Ratio of Satisfactory Results (Comparison method) Nominal length Ratio of Satisfactory Results (%) APLACEAIAAC 1 mm9483100 10 mm9192 88 100 mm8592 88 average 90 %

21. Examination of the Results Possible Causes for Unsatisfactory Results  long term drift of reference standards,  effect by measuring instrument,  thermal influence and deformation influence of gauges,  miscalculation of data,  underestimation of uncertainty, etc.,

22. Examination of the Results Details of Uncertainties of Outlier Results Measurement method Number of all outlier results Number of results smaller than the uncertainties of reference value Number of results smaller than the median of uncertainties of all participants Interferometry 200 Comparison 221 17 (77 %)

23. 95 % Satisfactory Results 95 % Level of Confidence (Uncertainty) Examination of the Results Outlier Results Small Uncertainty Low Satisfactory Results (90 %) If Median Uncertainty applied to Outliers? Outlier Results Median Uncertainty One cause may be Underestimation!!!

24. Conclusion  86 labs participated from all over the world true world- wide ILC program  Over 90 % of results are satisfactory many of labs have well established technical competence  Difference between regions was small measurement traceability is well established on the global level  Outlining results might be cased by underestimation of claimed uncertainties.

25. Thank you for your attention. International Accreditation Japan (IAJapn) http://www.iajapan.nite.go.jp/iajapan/