Final Report CCM.V-K2 Comparison

Transcription

1 Final Report CCM.V-K2 Comparison C. Patrick Maggi, David Trowbridge, M Thomas Zubler Cannon Abstract This report describes the second CCM key comparison in capillary viscometry at nine National Metrology Institutes (NMIs), which was carried out between April and August Five NMIs, which do not maintain an independent viscosity scale, also took part in this comparison. One participant submitted changes to their originally submitted results for one liquid and requested that results be withdrawn for a second liquid. Six samples of Newtonian liquids with nominal kinematic viscosities of 80 mm²/s at - 40 C, 20 mm²/s at -20 C, 5 mm²/s at 20 C, 1300 mm²/s at 20 C, 40 mm²/s at 100 C and 15 mm²/s at 150 C were used to determine the degrees of equivalence between the individual NMIs and the proposed key comparison reference values (KCRV). From the total number of 54 measurements carried out by all the participating NMIs, 7 measurements (13%) showed deviations from the proposed KCRVs greater than were covered by the measurement uncertainties. This compares to 18 deviations (24%) out of 74 total measurements made in the first key comparison. Linkage to the first key comparison is found at two points - approximately 1300 mm 2 /s at 20ºC and 40 mm 2 /s at 100 C. For this key comparison, 13% of the measurements (3 out of 23) on these two points exceeded the proposed KCRVs by more than were covered by the respective measurement uncertainties. For reference, the first CCM viscosity key comparison (CCM.V-K1) was conducted in 2002.

2 Table of Contents 1. INTRODUCTION LIST OF PARTICIPANTS VISCOSITY SCALES OF THE PARTICIPANTS LIQUID SAMPLES ORGANIZATION OF THE COMPARISON COMMENTS ON THE COMPARISON RESULTS OF THE CCM.V-K2 COMPARISON REFERENCES APPENDICES...13 Appendix A1 Summary of Degrees of Equivalence and Uncertainties, with Charts Appendix A2 Technical Protocol Appendix A3 Original Timetable CCM V K2 Final Report Feb doc Page 2 of 36

3 1. Introduction The organization of the second key comparison on viscosity was planned at the CCM Working Group on Viscosity meeting held April 26, 2005 at the BIPM in Sevres, France. Members agreed that all laboratories eligible under the rules of CIPM Mutual Recognition Arrangement (CIPM MRA) could participate in the key comparison. NIST /Cannon Instrument (USA) agreed to be the pilot laboratory for the comparison, with the Physikalisch - Technische Bundesanstalt PTB (Germany) offering assistance as a working party. The goal of this second key comparison was to compare viscosity measurement results at temperatures below and above the range of the first key comparison (CCM.V-K1), specifically -40ºC, -20ºC and 150ºC. In addition, measurements at 20 C and 100 C were included to provide linkage to the first key comparison. The proposed key comparison reference values (KCRV) were established from the results submitted by those laboratories maintaining an independent viscosity scale. Nine participating NMI laboratories maintained an independent viscosity scale. Five additional participants took part in this comparison. The organization of this key comparison followed the conventions of the first comparison where possible. CCM V K2 Final Report Feb doc Page 3 of 36

4 2. List of Participants Dr. Salvatore LOREFICE Instituto Nazionale di Ricerca Metrologica Strada Delle Cacce Torino Dr. Maria FERREIRA Portugues da Qualidade Laborotorio Cental de Metrologia Rua Antonio Giao 2, Caparica Dr. Mohamed MEGHARFI Laboratoire National de Metrologie et d Essias 25 Avenue Albert Bartholome Paris Dr. Mostafa MEKAWY Thermometry Lab National Institute for Standard 4 Tersa Street E1Haram Giza Mr. Martijn VAN RIJN NMI Van Swinden Laboratorium B.V., Section of Chemistry PO Box 654, 2500 AR Delft Thijsseweg 11, 2629 JA Delft Dr. Yoshitaka FUJITA National Metrology Institute of Japan(NMIJ), Fluid Properties Section, National Institute of Advanced Industrial Science and Technology AIST Central 3, Umezono Tsukuba, Ibaraki Dr. Xuelin XU National Institute of Metrology of P.R. China, Department of R&D and Planning (International Cooperation) No. 18 Beisanhuandonglu, Chaoyang District, Beijing, INRiM IPQ * LNE NIS * NMi NMIJ NIM Italy Portugal France Egypt The Netherlands Japan China CCM V K2 Final Report Feb doc Page 4 of 36

5 Dr. Henning WOLF Physikalisch-Technische Budnesanstalt, Braunschweig und Berlin Bundesallee Braunschweig Dr. Natalia G. DOMOSTROEVA 19 Moskovsky Pr St. Petersburg Mr. Dalni MALTA Instituto Nacional de Metrologia Av. Nossa Senhora das Gracas 50 Predio 3 Dr. Dusan TROCHTA Slovak Institute of Metrology, Slovensky Metrologicky Ustav Centrum hmotnosti a tlaku, Centre of Mass and Pressure Karloveska 63 SK Bratislava Dr. Dragos BOICIUC Institutul National de Metrologie Sos. Vitan-Barzesti 11, Sector 4 Bucuresti Mr. Christian BUCHNER Bundesamt fur Eich und Vermessungswesen (Federal Office of Metrology and Surveying), Masse und verwandte Groben(Mass and Realted Quantities) Arltgasse 35 A1160 Wein Mr. Thomas ZUBLER Cannon Instrument Company, National Institute of Standards and Technology 2139 High Tech Rd. State College, PA PTB VNIIM INMETRO * SMU INM * BEV * NIST/CANNON Germany Russia Brazil Slovakia Romania Austria United States * Laboratories not reporting an independent viscosity scale. CCM V K2 Final Report Feb doc Page 5 of 36

6 3. Viscosity Scales of the Participants The first key comparison established the validity of the laboratory viscosity scales and their step up procedures from the generally accepted standard value of water ( mm²/s) [1]. Additional discussions about the viscosity scales of several participants can be found in the first key comparison [2]. The viscosity measurement uncertainty budgets for each participating laboratory are included in Appendix A3. 4. Liquid Samples Cannon Instrument Company, as pilot laboratory, provided participating laboratories with samples of Newtonian standard liquids for measurement. Each 470 ml sample bottle was labelled as liquid A or liquid B and by the designated test temperature, for example Liquid A -40. Originally the protocol (Appendix A4) specified that both liquids were poly-alpha-olefins. However, upon pre-testing of the samples by Cannon, it was determined that crystallization of the Liquid A could occur at temperatures above the target test temperature of 40 C. Therefore, the Liquid A was changed to a base stock mineral oil having an established history of use as a viscosity standard by Cannon from 1958 to the present. The pilot laboratory provided the following revised data for the samples: Table 4-1: Standard Liquid Material Parameters Standard Liquid A (mineral oil) Liquid B (poly-alphaolefin) Temperature ( C) Nominal kinematic viscosity (mm²/s) Density (g/cm 3 ) Surface tension (mn/m) CCM V K2 Final Report Feb doc Page 6 of 36

7 5. Organization of the Comparison Table 5-1: Chronology of Measurements Date Who What April 10, 2006 April 20, 2006 May 3, 2006 July 8, 2006 August 2, 2006 March 2007 Pilot Laboratory All Participants All Participants All Participants All Participants Pilot Laboratory The original timetable is shown in Appendix A2. Shipment of the standard liquids, the data sheets, the timetable, and the technical report to the participants Start of the comparison measurements Receipt of the samples by the final participant Finishing of the comparison measurements Submission of the final results to the pilot laboratory Submission of Draft Report A, Revision 1 to the participants 6. Comments on the Comparison The sample shipment date was delayed from the original timetable due to a change in material (see section 4) for one of the samples. The samples arrived at the participant s laboratories between April 12 th and May 3 rd, Testing of the samples occurred during the period of May 8 th through July 8 th. The pilot laboratory received measurement results by July 31 st, with final uncertainty information received on Aug 2 nd. Not all participants chose to perform measurements at each temperature. Following the compilation of the data for the draft A report, two participants were asked to verify their submitted results. One of the participants reviewed their data and established that no errors existed. VNIIM reviewed their data and submitted corrections to their reported data for Liquid A 20C. These corrections appeared to be for typographical or transcription errors. VNIIM also requested that their submitted results for Liquid A-40C be withdrawn. These results were withdrawn from the draft A report and noted in associated tables and charts. CCM V K2 Final Report Feb doc Page 7 of 36

8 Laboratory Table 6-1: Participation Roster Standard Liquid A Standard Liquid B -40 C -20 C 20 C 20 C 100 C 150 C Cannon X X X X X X INRiM X X X X LNE X X X X X X NMi X X NMIJ/AIST X X X X NIM X X PTB X X X X X X SMU X X VNIIM withdrawn X X X X BEV X X X X X INM X X X X X X INMETRO X X X IPQ X X NIS X X * Bold text denotes laboratory with independent viscosity scale The measurement report form was designed to follow the Guide to the Expression of Uncertainty in Measurement [3]. A table for the uncertainty budget was included with the measurement report form, for completion by each participating laboratory. Several comments were submitted with certain test results: PTB noted that when measuring liquid B, the first few measurements had continuously decreasing efflux times and thus used efflux times 6 through 10. The participant did not attribute this to temperature instability. NMi noted a problem when using three Ostwald viscometers (two for reporting and a third for validation). Successive efflux times for each filling were consistent. However, the average efflux times were significantly different between fillings (approximately 1% longer). This trend carried forward to a third filling (an additional 1% longer). This anomaly was observed only on sample Liquid B at 100 C. The participant did not attribute this to temperature instability or improper cleaning of the viscometers. SMU reported using only 1 filling of the Liquid B at 20 C because the bottle was broken and only one charge of the material could be saved. The sample was filtered for glass particulates prior to measurement. CCM V K2 Final Report Feb doc Page 8 of 36

9 No definitive cause has been determined for the situations reported by the first two of these three participants. 7. Results of the CCM.V-K2 Comparison The measurement results are compiled in Table A1-1 through A1-6 in Appendix A1. In these tables, a bold font indicates data provided by the participants. Cells with a cross indicate the participant did not submit results for that liquid and temperature. The temperature corrected (normalized) kinematic viscosity result for each participant is listed in column V (mm 2 /s). The columns labeled D xxx contain the degrees of equivalence of each measurement with the xxx central tendencies: mean, weighted mean, and weighted median. The U(D xxx ) columns are the expanded uncertainty for the degrees of equivalence. Discrepant values [6] at the 5% level of significance are noted by red text in the columns with the heading: U(D xxx ) - D xxx. A graphical representation of the Degree of Equivalence to the KCRV is displayed in the Figures A1-1 through A1-6. Degree of Equivalence between two laboratories is defined as the difference in results obtained by the two laboratories [expressed as D ij =D i -D j, ] and the expanded uncertainty of those values at a 95% confidence level [U ij =2(u i 2 +u j 2 ) 1/2 ]. The results are given in Tables A1-1a through A1-6a. Tables A1-1 through A1-6 also list for each fluid and temperature the mean, weighted mean, and weighted median with their respective uncertainties (k=1) as u a and their respective relative expanded uncertainties (k=2) as U r. Associated with each of these potential KCRV estimators is the difference between its value and the proposed KCRV value, with the uncertainty (k=2) of the difference as 2*((u a xxx ) 2 + (u a KCRV ) 2 ) ½. [7] A consistency check based on each of the three KCRV candidates was performed using a chi-squared test. [6] Data sets that failed the consistency check, Pr{χ 2 (υ) > χ 2 obs} < 0.05 (υ is the degrees of freedom) are indicated in red text. If a data set failed the consistency check using the weighted mean, then the weighted median was proposed as the KCRV. The consistency check failed for the data sets of Liquid A -20C, Liquid B 100C, and Liquid B 150C. The KCRV values were derived from the results reported by those laboratories that maintain an independent viscosity scale. A total of fourteen laboratories participated in this comparison. Nine of those participants have performed a calibration program of primary viscometers beginning with water at 20.00ºC (ISO ) [1] and stepping up to higher viscosities in a dependent progression. This comparison included two different fluids and five test temperatures. While all laboratories reported results at 20 C, some laboratories did not report results for all five temperatures (see Table 6-1). The kinematic viscosity results reported by each participant are tabulated in Table A1-1 as V 0 and the kinematic viscosity normalized to the target temperature is listed under the column heading, V. The expanded relative uncertainty listed in column U r is for a 95% confidence interval. The expanded relative uncertainty was calculated by the pilot laboratory using the coverage factor (k, 95% CI) derived from the submitted combined uncertainty and effective degrees of freedom, for those partici- CCM V K2 Final Report Feb doc Page 9 of 36

10 pants providing that information. The coverage factor submitted by the participants did not always agree with the value calculated by the pilot laboratory. In these cases, the calculated value was reported. Attention should be drawn to the small number of data points available for the data sets of Liquid A -40C, Liquid A -20C, and Liquid B 150C. The mean and weighted mean values and their expanded uncertainties (k=2) were calculated using standard Microsoft EXCEL functions. The weighted median values and their associated expanded uncertainties (k=2) were calculated following a Monte Carlo (MC) procedure [6] using statistical and matrix functions available in MathCAD. The expanded uncertainty (k=2) values for the participants without an independent scale were calculated for the differences from the mean and the weighted mean using equation 6 in the CCM.V-K1 Final Report [2]. The expanded uncertainty (k=2) values for the participants without an independent scale were calculated for the differences from the weighted median using the determination of a 95% coverage interval following the procedure described by Cox in Appendix B of The Evaluation of Key Comparison Data [6]. The data analysis was expanded to include consideration of the robust mean [4]. The equations for the calculation of robust mean values and the associated uncertainties are available in the Royal Society of Chemistry paper [5]. Table 7-1 is a tabulation of reported viscosities, means, robust means, standard deviations, and coefficients of variation (CofV). A comparison of CofV values suggests a notable dispersion of viscosity values for Liquid A-20C and Liquid B100C. The CofV values for these two samples are approximately an order of magnitude larger than the CofV values for the other data sets. Consequently, further statistical techniques were used to evaluate the data. Table 7-1: Evaluation of Central Tendencies Independent Viscosity Scales Robust Statistics - T i Corrected Liquid A Liquid B -40 C -20 C 20 C 20 C 100 C 150 C Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM Arithmetic Mean StdDev Coeff. Of Variation 0.03% 1.95% 0.08% 0.13% 0.87% 0.19% Robust Mean Robust StdDev Coeff. Of Variation 0.03% 0.39% 0.07% 0.14% 0.21% 0.22% CCM V K2 Final Report Feb doc Page 10 of 36

11 The practice in the previous key comparison CCM.V-K1 [2], of using the E n -criterion to quantify the compatibility between a measurement of an individual participant and the reference value, was repeated in this study. The results are tabulated in Table A1-7 in which the columns are arranged in sets of two for each liquid/temperature condition. The first of the two columns is V-V KCRV /V KCRV, the second is the result of the first column divided by (u r 2 i +u 2 KCRV), which is the normalized error, E n. Seven measurement values did not fulfill the criteria that E n 1 and are indicated by a yellow field. Linkage to the first key comparison is found at two points - approximately 1300 mm 2 /s at 20ºC and 40 mm 2 /s at 100 C. For this key comparison, 13% of the measurements (3 out of 23) on these two points exceeded the KCRVs by a value corresponding to the measurement uncertainties submitted by those participants. Table 7-4: Comparison to Past Key Comparison Results Parameter CCM.V-K1 CCM.V-K2 Comments Temperatures ( C) 20, 40, , -20, 20, 100, 150 Linkage at 20 and 100 Number of Samples 5 6 PAO and mineral oil Total Participants 18 (11 maintaining independent scale) 14 (9 maintaining independent scale) Total Measurements 74 54* Measurement deviations greater than measurement uncertainty 18 7 % Total Deviations 24% 15% *total does not include one withdrawn measurement. Limited participation at -40, -20, and 150 C Analyzed using the E n -criterion as defined in CCM.V-K1 CCM V K2 Final Report Feb doc Page 11 of 36

12 8. References 1 ISO TR 3666: Viscosity of Water (1998) 2 CCM.V-K1 Intercomparison, Günther Klingenberg and Harro Bauer PTB 3 Guide to the Expression of Uncertainty in Measurement, corrected and reprinted 1995, International Organization of Standardization (Geneva, Switzerland) 4 Robust Statistics: A Method of Coping with Outliers (AMC Technical Brief no. 6 Apr 2001, Analytical Methods Committee, Royal Society of Chemistry 2001) 5 Robust Statistics-How Not to Reject Outliers, Analytical Methods Committee, Analyst, December 1989, The Evaluation of Key Comparison Data, M. G. Cox, Metrologia, 2002, 39, Statistical Concepts in Metrology, Harry H. Ku, in Precision Measurement and Calibration, NBS Special Publication 300 vol. 1, 1969, page CCM V K2 Final Report Feb doc Page 12 of 36

13 9. Appendices Appendix A1 Summary of Degrees of Equivalence and Uncertainties, with Charts Table A1-1: Results of the CCM.V-K2 Comparison (Symbols defined within the text) CCM.V-K2 Comparison - Liquid A at -40ºC KCRV mean weighted mean median (Monte Carlo) V o Temp. / C V U r [95% CI] u a [k=1] D mean U(D mean ) [k=2] U(D mean ) - D mean D wtmean U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median U(D median ) [k=2] U(D median ) - D median Cannon Independent Scale INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM withdrawn BEV INM INMETRO IPQ NIS Mean Weighted Mean Median (MC) consistency check > > > 0.05 CCM V K2 Final Report Feb doc Page 13 of 36

14 Table A1-1a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid A at -40ºC Degrees of Equivalence Between Institutes Lab j Lab i Cannon LNE NMIJ / AIST PTB INM D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon LNE NMIJ / AIST PTB INM CCM V K2 Final Report Feb doc Page 14 of 36

15 Independent Scale Table A1-2: Results of the CCM.V-K2 Comparison (Symbols defined within the text) V o Temp. / C V U r [95% CI] u a [k=1] D mean KCRV mean weighted mean median (Monte Carlo) U(D mean ) [k=2] U(D mean ) - D mean D wtmean U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median U(D median ) [k=2] U(D median ) - D median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS CCM.V-K2 Comparison - Liquid A at -20ºC Mean Weighted Mean Median (MC) consistency check 7.2E-152 < E-07 < E-06 < 0.05 CCM V K2 Final Report Feb doc Page 15 of 36

16 Table A1-2a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid A at -20ºC Degrees of Equivalence Between Institutes Lab j Lab i Cannon LNE PTB VNIIM BEV INM D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon LNE PTB VNIIM BEV INM CCM V K2 Final Report Feb doc Page 16 of 36

17 Independent Scale Table A1-3: Results of the CCM.V-K2 Comparison (Symbols defined within the text) V o Temp. / C V U r [95% CI] CCM.V-K2 Comparison - Liquid A at 20ºC u a [k=1] D mean KCRV mean weighted mean median (Monte Carlo) U(D mean ) [k=2] U(D mean ) - D mean D wtmean U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median U(D median ) [k=2] U(D median ) - D median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS Mean Weighted Mean Median (MC) consistency check 0.12 > > > 0.05 CCM V K2 Final Report Feb doc Page 17 of 36

18 Table A1-3a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid A at 20ºC Degrees of Equivalence Between Institutes Lab j Lab i Cannon INRiM LNE NMi NMIJ / AIST NIM PTB D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij / mm2/s Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS SMU VNIIM BEV INM INMETRO IPQ NIS D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij / mm2/s Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS CCM V K2 Final Report Feb doc Page 18 of 36

19 Table A1-4: Results of the CCM.V-K2 Comparison (Symbols defined within the text) Independent Scale V o Temp. / C V U r [95% CI] u a [k=1] D mean KCRV mean weighted mean median (Monte Carlo) U(D mean ) [k=2] U(D mean ) - D mean D wtmean / mm2 /s U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median / mm2 /s U(D median ) [k=2] U(D median ) - D median Cannon INRiM LNE NMi CCM.V-K2 Comparison - Liquid B at 20ºC NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS Mean Weighted Mean Median (MC) consistency check 0.44 > > > 0.05 CCM V K2 Final Report Feb doc Page 19 of 36

20 Table A1-4a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid B at 20ºC Degrees of Equivalence Between Institutes Lab i Lab j Cannon INRiM LNE NMIJ / AIST NIM PTB D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon INRiM LNE NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS SMU VNIIM BEV INM INMETRO IPQ NIS D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon INRiM LNE NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS CCM V K2 Final Report Feb doc Page 20 of 36

21 Independent Scale Table A1-5: Results of the CCM.V-K2 Comparison (Symbols defined within the text) V o Temp. / C V U r [95% CI] u a [k=1] D mean KCRV mean weighted mean median (Monte Carlo) U(D mean ) [k=2] U(D mean ) - D mean D wtmean U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median U(D median ) [k=2] U(D median ) - D median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS CCM.V-K2 Comparison - Liquid B at 100ºC Mean Weighted Mean Median (MC) consistency check 8.6E-45 < E-03 < E-03 < 0.05 CCM V K2 Final Report Feb doc Page 21 of 36

22 Table A1-5a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid B at 100ºC Degrees of Equivalence Between Institutes Lab j Lab i Cannon INRiM LNE NMi NMIJ / AIST D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon INRiM LNE NMi NMIJ / AIST PTB VNIIM BEV INM INMETRO PTB VNIIM BEV INM INMETRO D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon INRiM LNE NMi NMIJ / AIST PTB VNIIM BEV INM INMETRO CCM V K2 Final Report Feb doc Page 22 of 36

23 Independent Scale Table A1-6: Results of the CCM.V-K2 Comparison (Symbols defined within the text) V o Temp. / C V U r [95% CI] u a [k=1] D mean KCRV mean weighted mean median (Monte Carlo) U(D mean ) [k=2] U(D mean ) - D mean D wtmean U(D wtmean ) [k=2] U(D wtmean ) - D wtmean D median U(D median ) [k=2] U(D median ) - D median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS CCM.V-K2 Comparison - Liquid B at 150ºC Mean Weighted Mean Median (MC) consistency check 1.0E-05 < E-04 < E-06 < 0.05 CCM V K2 Final Report Feb doc Page 23 of 36

24 Table A1-6a: Results of the CCM.V-K2 Comparison Between Institutes CCM.V-K2 Comparison - Liquid B at 150ºC Degrees of Equivalence Between Institutes Lab i Lab j Cannon INRiM LNE PTB BEV INM D i U i D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij D ij U ij Cannon INRiM LNE PTB BEV INM CCM V K2 Final Report Feb doc Page 24 of 36

25 Table A1-7: Calculated Values of Normalized Error CCM.V-K2 Comparison - Calculated Values of Normalized Error, E n Liquid A -40C Liquid A -20C Liquid A 20C Liquid B 20C Liquid B 100C V-V KCRV / prev. col. / V-V KCRV / prev. col. / V-V KCRV / prev. col. / V-V KCRV / prev. col. / V-V KCRV / prev. col. / V-V KCRV / prev. col. / V KCRV (u 2 r +u 2 KCRV) ½ V KCRV (u 2 r +u 2 KCRV) ½ V KCRV (u 2 r +u 2 KCRV) ½ V KCRV (u 2 r +u 2 KCRV) ½ V KCRV (u 2 r +u 2 KCRV) ½ V KCRV (u 2 r +u 2 KCRV) ½ Cannon 2.6E E E E E E INRiM 9.5E E E E LNE 5.2E E E E E E NMi 8.2E E NMIJ / AIST 1.1E E E E NIM 1.0E E PTB 1.4E E E E E E SMU 1.5E E VNIIM 3.9E E E E BEV 6.7E E E E E INM 5.6E E E E E E INMETRO 1.5E E E IPQ 1.5E E NIS 5.9E E Liquid B 150C CCM V K2 Final Report Feb doc Page 25 of 36

26 Figure A1-1: Liquid A -40C Degrees of Equivalence V - V KCRV weighted mean Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS withw/o IVS drawn uh ul CCM V K2 Final Report Feb doc Page 26 of 36

27 Figure A1-2: Liquid A -20C Degrees of Equivalence V - V KCRV median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS w/o IVS uh "ul" CCM V K2 Final Report Feb doc Page 27 of 36

28 Figure A1-3: Liquid A 20C Degrees of Equivalence V - V KCRV weighted mean Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS w/o IVS uh "ul" CCM V K2 Final Report Feb doc Page 28 of 36

29 Figure A1-4: Liquid B 20C Degrees of Equivalence V - V KCRV weighted mean Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS w/o IVS uh ul CCM V K2 Final Report Feb doc Page 29 of 36

30 Figure A1-5: Liquid B 100C Degrees of Equivalence V - V KCRV median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS w/o IVS uh ul CCM V K2 Final Report Feb doc Page 30 of 36

31 Figure A1-6: Liquid B 150C Degrees of Equivalence V - V KCRV median Cannon INRiM LNE NMi NMIJ / AIST NIM PTB SMU VNIIM BEV INM INMETRO IPQ NIS with IVS w/o IVS uh ul CCM V K2 Final Report Feb doc Page 31 of 36

32 Appendix A2 Technical Protocol Technical Protocol for the CCM Key Comparison of the Viscosity CCM.V K2 Pilot Laboratory: NIST / Cannon Instrument (J. Whetstone, G. Strouse / P. Maggi, D. Trowbridge, T. Zubler) Working Party: Physikalisch Technische Bundesanstalt (H. Bauer) Outline of the CCM key comparison of the viscosity This key comparison, CCM.V-K2, has been undertaken by the CCM Working Group on Viscosity to compare the viscosity determinations of participating laboratories. The four objectives are: Compare viscosity measurements at temperatures outside of the range of the first key comparison. Compare viscosity measurements made at -40ºC and at -20ºC using a standard fluid designated as Liquid A. Compare viscosity measurements made at 150ºC using a standard fluid designated as Liquid B. Compare results from this key comparison to results from the previous key comparison using viscosity measurements made at 20ºC and at 100ºC involving both Liquid A and Liquid B. Certain participants have performed a calibration program of primary viscometers beginning with water at 20.00ºC (ISO ) [1] and stepping up to higher viscosities in a dependent progression. Results from these participants will contribute to the reference value obtained from this comparison. The noncontributing participants will be providing viscosities determined from viscometers calibrated by other metrology institutes. (A list of the addresses of the contributing and non-contributing participants will be established later, coordinated by Dr. Davis.) The results of this comparison will be of interest for the entries concerning viscosity in the Calibration and Measurement Capability (CMC) tables. Purpose of this document The purpose of this document is to provide the participating laboratories with instructions for the handling of the liquid samples and to report on the measurement results and the measuring procedure. It is important that all instructions given in this document be followed. This will ensure that the measurement data are obtained under comparable conditions and are presented in the same format. Any deviation from the instructions has to be reported to the pilot laboratory. CCM V K2 Final Report Feb doc Page 32 of 36

33 Liquid samples The measurements are to be carried out on samples of two standard liquids provided by NIST/Cannon as the pilot laboratory. Both samples are poly-α-olefines, not labelled as dangerous goods. Standard liquid A, approximate kinematic viscosity at -40 C / -20 C / 20 C: 150 mm²/s / 35 mm²/s / 7 mm²/s density: to be specified surface tension: to be specified Standard liquid B, approximate kinematic viscosity at 20 C / 100 C / 150 C: 1300 mm²/s / 40 mm²/s / 15 mm²/s density: to be specified surface tension: to be specified For both standard liquids, the long term stability of the kinematic viscosity is better than 0.1% over 6 month. Exposure to bright light and high temperatures should be avoided. The sealed glass bottles should not be opened before the measurements are started. The oils may be heated to 70 C to facilitate filling of the viscometers. Format for reporting the measurement results The information is to be given for each liquid. Please use: Report_ Form_1_A_-40 C for liquid sample A, -400 C Report_ Form_1_A_-20 C for liquid sample A, -20 C Report_ Form_1_A_20 C for liquid sample A, 20 C Report_Form_1_ B_20 C for liquid sample B, 20 C Report_ Form _1_B_100 C for liquid sample B, 100 C Report_Form_1_ B_150 C for liquid sample B, 150 C CCM V K2 Final Report Feb doc Page 33 of 36

34 Uncertainty of measurement All of the report forms (1A -40 C, 1A -20 C, 1A 20 C, 1B 20 C, 1B 100 C, 1B 150 C ) give a list of main components of the uncertainty budget. Please add any additional component occurring in your measurements. Do not include a term for a potential long-term drift of the viscosity. The uncertainty of the viscosity is to be given as one standard uncertainty and in addition as expanded uncertainty U 95 for a confidence level of 95%. This is obtained by combining the individual standard uncertainties obtained from Type A and Type B evaluations. The uncertainty evaluation should include a list of all influence quantities, their values and standard uncertainties, together with their degrees of freedom. The combined standard uncertainty, as well as the effective degrees of freedom ν eff of the combined standard uncertainty u c and the t-factor t 95 (ν eff ) taken from the t-distribution for a 95% confidence level must be stated. The expanded uncertainty is given as U 95 = t 95 (v eff ) u c. The uncertainties are to be calculated and reported according to ISO "Guide to the Expression of Uncertainty in Measurement" [2]. Details of viscosity measurement Give the mathematical model equations for calculating the viscosity of the liquid g ν = C( t t ) c In this equation, ν is the kine- samples. (Example: KE S gcal matic viscosity in mm²/s, g is the acceleration of free fall at the point of measurement in m²/s, g cal is the acceleration of free fall at the point of calibration, C is the viscometer constant in mm²/s², t is the flow time in s, t KE the kinetic energy correction in s, and c S the surface tension correction factor.) Describe how the standard uncertainties of the individual influence quantities of Report Form 1 in the uncertainty of the viscosity were estimated. It is important to know in what way the participants calibrated the viscometers used in this comparison. Concerning the additional participants, it is important to know the source of the calibration certificate. Please give references to publications concerning your viscosity scale. If possible, send a copy of the publication to the Pilot Laboratory. Deadline The reports are to be sent to the Pilot laboratory as soon as possible and four weeks after the measurements are completed at the latest. A result is not considered complete if no associated uncertainty supported by a complete uncertainty budget is given. The results are confidential until all the participants have completed their measurements and all the results have been received (or until the deadline for receipt of the results is over). CCM V K2 Final Report Feb doc Page 34 of 36

35 [1] ISO TR 3666: Viscosity of water 1998 [2] Guide to the expression of Uncertainty in Measurement, corrected and reprinted 1995, International Organization of Standardization (Geneva, Switzerland) CCM V K2 Final Report Feb doc Page 35 of 36

36 Appendix A3 Original Timetable Starting date: March 15 st, 2006 Timetable: March 15 th, 2006 (pilot laboratory): Mailing of the standard liquids, the data sheets, the timetable, and the technical report to the participants April 20 th, 2006 (all participants): Start of the comparison measurements May 25 th, 2006 (all participants): Finishing of the comparison measurements June 26 th, 2006 (all participants): Submission of the results to the pilot laboratory Aug 1 st, 2006 (pilot laboratory): Submission draft report A to the participants October 20 th, 2006 (BIPM): Submission of draft B In the case of unexpected delay at a participant institute it is possible, that these data cannot be taken into account. CCM V K2 Final Report Feb doc Page 36 of 36