Final Report on Key Comparison EUROMET.M.P-K3.a in the Gauge Pressure Range 50 kpa to 1000 kpa. May 2005

Transcription

1 Final Report on Key Comparion EUROMET.M.P-K3.a in the Gauge Preure Range 50 kpa to 1000 kpa Pierre OTAL 1, Jo VERBEEK 2, Ditmar STEINDL 3, Jiri TESAR 4, Vladimir N. GOROBEI 5, Carmen MATILLA VINCENTE 6, Iabel SPOHR 7 May 2005 ABSTRACT The tandard of 7 European Laboratorie in the preure range from 100 to 1000 kpa, with an option at 50 kpa, have been compared in the period The tranfer tandard wa a preure balance equipped with a ga-lubricated piton-cylinder aembly of nominal effective area 980 mm². Thi aembly wa formerly ued a tranfer tandard for the key comparion CCM.P-K1.b. At the time of the comparion, the reult relating to the effective area were not publihed. The link of the EUROMET.M.P-K3a comparion to CCM.P-K1.b will be etablihed through the reult of LNE, acting a the pilot laboratory. The comparion protocol for the EUROMET comparion wa the ame a for the CCM one. A the difference between the CCM reference value and the EUROMET reference value wa not ignificant, the CCM reference value ha been ued to etablih the equivalence tatement of the participant to the EUROMET.M.P-K3a comparion to CCM.P-K1.b. The deviation from the reference value of all the laboratorie but one are le than their etimated expanded uncertainty. Over 21 combination of pair of European laboratorie, 18 demontrate equivalence of the reult at 1 MPa. 1 Laboratoire National de Métrologie et d'eai, France (LNE) 2 Van Swinden Laboratorium B.V., The Nederland (NMi) 3 Bundeamt für Eich-und Vermeungween, Autria (BEV) 4 Czech Metrology Intitute, Czech Republik (CMI) 5 D.I. Mendeleyev Intitute for Metrology, Ruia (VNIIM) 6 Centro Epanol de Metrologia, Spain (CEM) 7 Intituto Portuguê da Qualidade, Portugal (IPQ) 1 EUROMET.M.P -K3

2 1. INTRODUCTION Thi work i a part of the EUROMET project n 439 (comparion in the preure range 0,05 to 7 MPa) coordinated by NPL. The purpoe of EUROMET project n 439, phae a, i to carry out a comparion in the range 50 kpa to 1 MPa. It i identified in the BIPM databae a the EUROMET.M.P-K3.a key comparion. The tranfer tandard had been ued previouly for the comparion CCM.P- K1.a (dimenional meaurement) and CCM.P-K1.b (preure meaurement). The LNE i pilot for the EUROMET.M.P-K3.a comparion. The EUROMET.M.P-K3.b comparion, in the range from 80 kpa to 7 MPa, i piloted by the NPL. Thi document give the reult of the EUROMET.M.P-K3.a comparion. Seven laboratorie have participated in the comparion between March 2000 and June The lit of the laboratorie, with the metrologit who took part in the work, i given below in the chronological order: Country Intitute Participant Meaurement date France Laboratoire National d'eai (LNE), initial Pierre OTAL, Thierry GALLIER, Jean Claude LEGRAS March 2000 The Netherland NMI Van Swinden Laboratorium B.V. (NMi) Jo VERBEEK April 2000 Autria Czech Republic Bundeamt für Eich-und Vermeungween (BEV) Czech Metrology Intitute (CMI) Ditmar STEINDL July 2000 Jiri TESAR October 2000 Ruia D.I. Mendeleyev Intitute for Metrology (VNIIM) Vladimir N. GOROBEI, Yurij A. KISELEV February 2001 Spain Centro Epanol de Metrologia (CEM) Carmen MATILLA VINCENTE, Salutiano RUIZ GONZALEZ April 2001 Portugal Intituto Portuguê da Qualidade (IPQ) Iabel SPOHR, Joé CONCEIÇAO, Lui BRITO May 2001 France Laboratoire National d'eai (LNE), final Pierre OTAL, Thierry GALLIER, Jean Claude LEGRAS June EUROMET.M.P -K3

3 2. TRANSFER STANDARD The tranfer tandard ued in the comparion i a preure balance model 5111, n It i equipped with the piton-cylinder aembly n 6594 of nominal effective area 980 mm². Both preure balance and piton cylinder aembly were manufactured by DESGRANGES & HUOT and circulated without mae. A 100 kg-et of mae calibrated with a relative uncertainty of about 1x10-6 i upplied by the laboratorie. Both the piton and the cylinder were made of tungten carbide with a linear thermal expanion coefficient of 4, C -1. The preure ditortion coefficient λ wa previouly calculated at a value of 4,0 x Pa -1. All the other data relative to the tranfer tandard were given by the pilot laboratory in the meaurement intruction, at the exception of the effective area at 20 C and null preure A 0. The comparion fluid wa dry nitrogen. The meaurement intruction were the ame a for the previou CCM.P-K1 b comparion. 3. TRANSFER STANDARD STABILITY The tranfer tandard wa calibrated two time at the LNE: LNE1 in March 2000 and LNE2 in June The figure 1 how the difference between the reult of the effective area A 0 determination by LNE for the CCM.P-K1 b comparion, then before (initial calibration) and after (final calibration) the circulation for the EUROMET comparion. In the 3 cae, the effective area A 0 ha been calculated from the effective area calculated a a function of the preure A p value a: ' A 0 ' Ap = ' 1+ λ. p In the figure 1, the difference are repreented a the relative deviation from the A 0 CCM reference value. The maximum relative difference of A 0 between the calibration before and after the EUROMET comparion wa 4,4 10-6, at the 600 kpa preure. Thi hift ha been taken into account in the calculation of the uncertainty of the difference between the laboratorie, in 6.2. Deviation from the CCM value / x CCM.P-K1b Initial calibration Final calibration Preure / kpa Fig 1. Stability of the piton-cylinder a oberved at LNE 3 EUROMET.M.P -K3

4 4. LABORATORY STANDARDS AND MEASUREMENT METHODS Each laboratory provided the pilot laboratory with the information related to the laboratory tandard. The tandard of all the laboratorie were preure balance. A few comment on the type of the piton-cylinder aembly, and the way of determination of the effective area, are given in table 1. Laboratory Standard, reference Range Effective area A o (mm 2 ) Standard uncertainty of A o (in 10-6 ) Preure dit. coeff. λ (in 10-6 MPa -1 ) Method of determination of A o LNE, 1 MPa PC N 5 0,01-1 MPa 980, ,2 4,0 ± 0,2 (calculated) Method a [1] NMi, 310 0,1-1 MPa 980, ,5 4,2 ± 0,8 (calculated) Method a BEV, ,02-4 MPa 98, ,86 ± 0,06 Method b CMI, 1 2 0,005-0,8 MPa 0,025-2 MPa 980, , ,75 5 5,5 ± 0,15-1,83 ± 0,15 Method a [3-5] VNIIM, NN11 NN10 0,1-0,5 MPa 0,3-3 MPa 1994, , ,5 8,6 6,84 ± 0,3 1,80 ± 0,5 Method a (*) [6-7] CEM, ,05-1 MPa 0,05-1 MPa 980, , ,3 ± 0,25 (calculated) Method b (**) IPQ, LCM ,01-2 MPa 490, (1,47 ± 0,15) Method b Method a: effective area calculated from dimenional meaurement (*) The VNIIM tandard i oil-operated, ued with an oil-ga interface Method b: effective area obtained by traceability to another laboratory (**) The CEM traceability i to another laboratory, but the A o value had been getting from dimenional meaurement. Table 1 - General detail of the reference tandard of the participating laboratorie. It wa recommended that each laboratory hould ue a data heet reporting the data obtained at each comparion point. The laboratorie were alo required to report the average data and to lit the uncertainty component to etimate the uncertainty of A' o. The comparion were performed at the nominal preure of: (0,05) ; 0,1 ; 0,2 ; 0,4 ; 0,6 ; 0,8 ; 1 ; 1 ; 0,8 ; 0,6 ; 0,4 ; 0,2 ; 0,1 ; (0,05) MPa. The meaurement were performed for 5 cycle. The meaurement at 0,05 MPa were optional and carried out at the LNE and the CEM only. The CMI performed 3 preure cycle only. The VNIIM performed meaurement at 0,1 MPa and 0,2 MPa with the laboratory tandard NN11 and the other preure point with the laboratory tandard NN10. The CEM performed 2 and half cycle with each of the above-mentioned tandard. 4 EUROMET.M.P -K3

5 5. REFERENCE VALUE The effective area of the piton-cylinder aembly of the tranfer tandard wa calculated a a function of the preure for each preure point. The effective area at null preure, corrected for the ditortion due to the preure, wa derived from thee reult. The nominal value of the preure ditortion coefficient wa ued to carry out the correction. The relative magnitude of the correction i 4 x 10-6 at 1 MPa. The reult reported in table 2 for each laboratory are the mean value of the effective area at null preure, a calculated from the 10 determination for preure value from 0,1 MPa to 1 MPa. The A' 0 value, and the tandard deviation of the value determined by each laboratory, have been reported a a function of the preure only to detect any potential tendency. Nominal preure (kpa) (50) LNE NMI BEV CMI VNIIM CEM IPQ Average 980, , , , , , , , , , , , , , , , , , , , , , , , ,500 0 A' 0 / mm² u A 0 / in , , , , , , , , , , , , , , , , , , , , , , , , ,492 8 Standard deviation (N=7) 4,0 4,4 4,4 3,9 4,8 4,4 Average 980, , , , , , , , ,7 (N=42) Table 2. Calculated effective area A 0 The average of the A o value obtained from the reult of all the laboratorie i: A 7 A0i, p p i= 1 ( EUROMET) = 980,4924 mm² 42 oref = The tandard deviation of the mean i: u R(EUROMET) / A oréf = 1,7 x 10-6 The ame tranfer tandard wa ued for the comparion CCM.P-K1.b: the ame meaurand A 0ref wa determined in both comparion. The reported reference value for the four laboratorie participating in the comparion - LNE, CNR-IMGC, NIST, PTB - wa: A' ( p', 20) 4 0i, p p i= 1 CCM = = 24 A 980,4929 mm² 5 EUROMET.M.P -K3

6 The experimental tandard deviation of the mean wa: u R(CCM) / X r = 0,65 x The relative difference between the average value A oref(euromet) for the EUROMET laboratorie and the CCM reference value i - 0,5 x A LNE wa the only laboratory involved in both the CCM and the EUROMET comparion, the ame reference value A '( p', 20) CCM a for the comparion CCM.P-K1.b a reported above ha been ued to evaluate the reult of the comparion. In order to have imilar reult for LNE in both comparion, the reult obtained for the CCM comparion have been ued for the ret of the comparion. For etablihing the equivalence tatement of the participating laboratorie, and to compare the reult of the EUROMET laboratorie to the CCM reference value, the relative uncertainty of the reference value wa calculated from the uncertainty etimated by each laboratory for the comparion CCM.P-K1.b: u ref 4 = 1/ 4 ²... 1 i u i lab ccm P K ) = = 1 ( 3, RESULTS 6.1. DEVIATIONS FROM THE REFERENCE VALUE The table 3 give, for each preure, the deviation of LNE from the CCM reference value, for both the CCM comparion and the EUROMET comparion. The tandard deviation of the deviation, and the equivalent tandard uncertainty are alo given in the table 3. The ame information i given in the table 4 for each laboratory. In that table, the deviation are calculated from the CCM reference value. In order to be conitent with the other comparion, the LNE value etablihed for the CCM comparion are kept for the ret of the analyi. LNE (CCM) LNE (EUROMET) Nominal preure (kpa) (50) + 5,2 1,1 3,9 + 5,8 1,0 7, ,9 0,6 3,4 + 0,2 0,5 7, ,4 0,8 3,1-2,6 0,3 6, ,2 0,4 3,0-2,6 0,2 6, ,2 0,3 2,9-2,1 0,3 6, ,1 0,3 2,9-1,7 0,3 6, ,6 0,3 2,9-0,9 0,3 6,6 Table 3. Reult of the pilot laboratory for both comparion: relative deviation from the CCM reference value A 0ref, relative tandard deviation of the difference, and tandard uncertainty 6 EUROMET.M.P -K3

7 In each cae, for the EUROMET comparion, the tandard uncertainty of the laboratory difference i calculated a the quadratic combination of u(a 0 ), the tandard uncertainty due to the tability of the tranfer tandard and the tandard uncertainty of the reference value u ref : 1 ' [ u A + u u ] 2 u diff = 0) + ( tab ref ( CCM ) The uncertainty for the tranfer tandard tability i calculated by uing a rectangular ditribution. u tab = 6 4, = 2,5 10 The reult from each participant are given in figure 2 (all participant) and figure 3 (5 participant only). It how, at each nominal preure, the relative deviation of the laboratory value from A 0ref. Relative difference / in LNE NMI BEV CMI VNIIM CEM IPQ Preure / MPa Fig 2. Relative deviation of the effective area from A 0ref 10 Relative difference / in LNE NMI CMI CEM IPQ Preure / MPa Fig 3. Relative deviation of the effective area from A 0ref 7 EUROMET.M.P -K3

8 LNE NMI BEV CMI VNIIM CEM IPQ Nominal preure (kpa) (50) + 5,2 1,1 3, ,1 0,8 8, ,9 0,6 3,4 3,6 0, , ,7 1,7 7,2-21 0,6 11-1,1 1,0 8,1 + 1,8 0, ,4 0,8 3,1 2,7 0, , ,8 1,4 6,9-21 0,5 11-4,5 0,6 8,1-0,7 0, ,2 0,4 3,0 2,2 0, , ,2 1,6 6,8-24 0,3 9,6-4,5 0,9 8,1-0,5 0, ,2 0,3 2,9 2,4 0, , ,9 1,6 6,8-20 0,4 9,6-4,2 1,1 8,1-0,2 0, ,1 0,3 2,9 1,7 0, , ,4 1,5 6,7-25 0,2 9,6-4,0 1,1 8,1-0,0 0, ,6 0,3 2,9 0,9 0, , ,3 0,0 6,6-22 0,3 9,6-3,7 1,3 8,1 + 0,2 0,2 23 Table 4. Relative difference from A 0ref, tandard deviation of the mean and relative tandard uncertainty 8 EUROMET.M.P -K3

9 610 For a purpoe of comparion, the figure 4 how effective area determined by the laboratorie for the comparion CCM.P.K1b [2]. Relative difference / in NIST CNR-IMGC PTB LNE Preure / kpa Fig 4. Relative deviation from A 0ref for the comparion CCM.P.K1b 6.2. UNCERTAINTIES AND EQUIVALENCES The figure 5, 6 and 7 how the equivalence of the reult oberved for each of the participant at kpa, kpa and kpa repectively. The uncertainty bar have been calculated a the combination of the uncertainty of the laboratory, the uncertainty of the reference value, and the uncertainty for the tranfer tandard tability. U diff = 2 u² i( lab) + u² ref + u² tab x Relative difference LNE10 LNE20 NMI10 NMI20 BEV100BEV20 CMI10 CMI20 VNIIM1VNIIM20 CEM10CEM20IPQ10 IPQ20 Fig 5. erence of each laboratory from the reference value at 100 kpa and 200 kpa 9 EUROMET.M.P -K3

10 x Relative difference LNE40 LNE60 NMI40 NMI60 BEV400BEV600 CMI40 CMI60 VNIIM40VNIIM6 CEM40CEM60 IPQ40 IPQ60 Fig 6. erence of each laboratory from the reference value at 400 kpa and 600 kpa x Relative difference LNE80 LNE100 NMI80 NMI100 BEV800 BEV100 CMI80 CMI100VNIIM80VNIIM10 CEM80 CEM10 IPQ80 IPQ100 Fig 7. erence of each laboratory from the reference value at 800 kpa and 1000 kpa The table 4 to 6 how the equivalence of pair of laboratorie for the preure 100 kpa, 600 kpa and 1 MPa. For each pair of laboratorie, the table give the oberved relative difference D ij and the expanded uncertainty of the difference U ij (k=2) calculated a the quadratic combination of the two laboratorie uncertaintie and the uncertainty from the tranfer tandard tability. 10 EUROMET.M.P -K3

11 Lab j LNE NMI BEV CMI VNIIM CEM IPQ Lab 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 LNE * * NMI 4 32 * * BEV * * CMI * * VNIIM * * CEM * * IPQ * * Table 4. Equivalence of pair of laboratorie at 100 kpa. The difference and the combined expanded uncertainty are expreed in Lab j LNE NMI BEV CMI VNIIM CEM IPQ Lab 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 LNE * * NMI 2 32 * * BEV * * CMI * * VNIIM * * CEM * * IPQ * * Table 5. Equivalence of pair of laboratorie at 600 kpa. The difference and the combined expanded uncertainty are expreed in Lab j LNE NMI BEV CMI VNIIM CEM IPQ Lab 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 LNE * * NMI 1 32 * * BEV * * CMI * * VNIIM * * CEM * * IPQ * * Table 6. Equivalence of pair of laboratorie at 1MPa. The difference and the combined expanded uncertainty are expreed in EUROMET.M.P -K3

12 7. CONCLUSION The reult of the comparion can be conidered a atifactory a the deviation from the reference value of all the laboratorie but one are inide the etimated uncertainty. The reult can be compared directly to the CCM.P.K1b comparion one: one of the two tranfer tandard ued for the CCM.P.K1b comparion ha alo been ued for the EUROMET.M.P-K3a comparion. Thi allowed the ue of the ame reference value for evaluating the reult. The average of the value iued from all the EUROMET laboratorie wa in fact in a very good agreement with the reference value reported for the CCM.P.K1b comparion: the relative difference between the two value wa 0,5 x Moreover, the hift of the effective area of the tranfer tandard oberved at LNE during both comparion wa not ignificant regarding the uncertaintie. REFERENCES [1] J.C. Legra, B. Schatz, P. Delajoud - La référence nationale de preion du BNM dan le domaine de 10 à 400 kpa. Bull. d'information du BNM N 65, (Juillet 1986). [2] J. C. Legra, W. Sabuga, G. F. Molinar, J. W. Schmidt - CCM.P.K1b Key Comparion in the Preure Range kpa (ga medium, gauge mode), BIPM data bae [3] J. Tear, Z. Krajicek and W. Schultz - Preure comparion meaurement between the CMI and the PTB in the range 0,07 MPa to 0,4 MPa", Metrologia Volume 36, 1999, p [4] M. H. Orhan, Y. Calkin, J. Tear and Z. Krajicek - Pneumatic gauge preure comparion meaurement between the UME (Turkey) and the CMI (Czech Republic) - EUROMET Project No. 537", Metrologia Volume 38, 2001, p. 173 [5] J. Tear - Development Preure Metrology", CMI Report 613-ZV-3812/1997 [6] V. Gorobey and all Comparion of the national preure tandard of the Ruian Federation (VNIIM), Germany (PTB) and Slovakia (SMU) in the preure range 1 MPa to 3 MPa", Metrologia Volume 36, 1999, p [7] Izmeritelnaÿa Tecknnika N 3, 1995, EUROMET.M.P -K3