ЕВРО-АЗИАТСКОЕ СОТРУДНИЧЕСТВО ГОСУДАРСТВЕННЫХ МЕТРОЛОГИЧЕСКИХ УЧРЕЖДЕНИЙ (KOOMET)

Transcription

1 ЕВРО-АЗИАТСКОЕ СОТРУДНИЧЕСТВО ГОСУДАРСТВЕННЫХ МЕТРОЛОГИЧЕСКИХ УЧРЕЖДЕНИЙ (KOOMET) EURO-ASIAN COOPERATION OF NATIONAL METROLOGICAL INSTITUTIONS (COOMET) Fal Report on the Torque Supplementary Comparison COOMET.M.T-S1 Measurand Torque: 0, 100, 500, 1500, 500 B. A. Cherepanov 1, D. Röske 1 Coordator, Ural Scientific Research Institute for Metrology, Rosstandart (UNIIM), 4 Krasnoarmeyskaya Str., Ekaterburg, Russian Federation cherepanov@uniim.ru Physikalisch-Technische Bundesanstalt (), Department 1. Solid Mechanics, Workg Group 1.1 Force Realization, Bundesallee 100, D Braunschweig, Germany dirk.roeske@ptb.de, Dr. Dirk Röske 1 Introduction This supplementary comparison the area of torque is based on the decision of COOMET Committee, agreed project 51/RU-a/10 (reg. BIPM KCDB as COOMET.M.T-S1). It has been planned that other laboratories may take part the present torque comparison performed by the COOMET. Ultimately UNIIM, Russian and, Germany participated the agreed project of comparisons. This comparison was conducted accordance with COOMET Recommendation R/GM/11:010 Regulations for comparison of measurement standards from the national metrological stitutes of COOMET. It covers torque standard maches of dead-weight type with a lever supported by air bearg or knife edge. used a supplementary comparison (Torque Standard Mache-TSM) 0-k-Dm-NME, with a lever supported by air bearg; UNIIM used a standard mache ЭУ-500 with a lever supported by knife edge. The aim of comparisons is to assess equivalence of the standard mache of UNIIM to the standard mache of РТВ, which was used key comparisons ССМ.Т-К, and, based on this assessment, to submit calibration and measurement capabilities of the measurement standard of UNIIM to the BIPM key comparison database. The comparison of the standard maches was carried out at the followg values of reproducible torque: 100, 500, 1500 and 500, clockwise as well as anticlockwise torque directions. Participants Table 1 The list of the participants of the comparison NMI, address 1 Ural Research Institute for Metrology 4 Krasnoarmeyskaya Str Ekaterburg Russian Federation Physikalisch-Technische Bundesanstalt Bundesallee Braunschweig Germany NMI abbreviation UNIIM Code sign U P Contact person, , telephone, fax B. A. Cherepanov cherepanov@uniim.ru Tel.: Fax: Dr. Dirk Röske dirk.roeske@ptb.de Tel.: +49 -(0)531/ Fax.: +49-(0)531/

2 3 Organization of comparisons For this study, a radial scheme has been selected accordg to which measurements are firstly conducted usg the mache of UNIIM and then these measurements are conducted usg the mache of and afterwards UNIIM repeats all measurements after their execution. Measurements are called UNIIM1 (U1), (P) and UNIIM3 (U3) 4 Comparison standard (CS) For these supplementary comparisons, a comparison standard belongg to UNIIM (Russia) is used. It consists of the followg items: Flange type torque transducer TB (3 kn m) with adapters. Data on the comparison standard is given table. Photographs of the transducer the shippg contaer and the amplifier are given Figure 1 and Figure. Table Specifications for the comparison standard Manufacturer Hottger Baldw Messtechnik GmbH, Germany Transducer of the comparison standard Model TB Serial No. # /3 k Size Ø 160 mm 64 mm (with adapters: Ø 160 mm 306 mm) Adapters Flanges with smooth couplg shafts Ø 60 h7 90 from both sides of comparison standard for connection to hydraulic couplgs Lenze ETP-60* Mass 14.6 kg (with adapters) Package Shippg contaer Specifications Resistance stra transducer Cable LEM 05-1., six-wire cable Connectors: FGG6 from the transducer side; DB-15 from the amplifier side Amplifier of the comparison standard ( a full set) model MGCplus Housg with power module TG009 Control panel АВА Front-end processor СР4 Backplane АР01i Amplifier ML38В * Participants of the comparison use their own ETP couplgs Figure 1 Transducer ТВ the shippg contaer Figure Amplifier MGCplus

3 The loadg scheme given Table 3 was used durg the comparison. Table 3 Comparison standard loadg scheme durg the comparison Position Loads 0 three itial prelimary loadgs (for stabilization) 0 one prelimary loadg, three measurg cycles (for assessg reproducibility) 10 one prelimary loadg, one measurg cycle 40 one prelimary loadg, one measurg cycle 360 one prelimary loadg, one measurg cycle 480 one prelimary loadg, one measurg cycle 600 one prelimary loadg, one measurg cycle 70 one prelimary loadg, one measurg cycle This loadg scheme is illustrated Figure 3. Figure 3 Sequence plot for measurement of torque durg comparisons The chronological sequence of calibrations durg the comparison is given Table 4. Table 4 Chronological sequence of calibrations durg the comparison Place of calibration TB clockwise anti-clockwise U Р U

4 5 Limitations of the comparison Limitation assessment is adopted for these comparisons, which was confirmed the process of key comparisons CCM.T-K, where it has been noted, that the hermetically closed transducer TB of the comparison standard was very stable, [1]. Nevertheless, order to get comparable results, some known sources of fluence on measurement results durg comparisons should be taken to account. Possible differences characteristics of the amplifiers beg used, that were assessed CCM.T-K, which amplifiers DMP40 of the participatg laboratories were is use, are absent case of these comparisons as one and the same amplifier is applied. In order to elimate the creepg effect, chronological scheme of loadg has been adopted. Its efficiency was confirmed CCM.T-K comparisons with the cycle time of 6 mutes, after which creepg comes to an end. At the same time several seconds deviation of one readg from the other has no major significance for measurement uncertaty. The change of the transducer stallation position of the comparison standard shall be implemented with 10 mutes. The effects of humidity (φ) and temperature (Т) on the measurement results may be significant, if air humidity and temperature the participatg laboratories differ considerably. Assumg that effect of humidity and temperature has equal absolute value both durg loadg with torque clockwise and anti-clockwise, it is possible to perform such assessment only when loadg the clockwise direction. In work [1] it has been shown that there is no need to conduct assessment of the effect of temperature under stable temperature conditions the participatg laboratories. As the maximum deviation of temperature conditions when performg present comparisons did not exceed.5 К, the assessment of the effect of temperature wasn t carried out. As relative humidity when conductg comparisons for different stages ranged from 19.8% to 53%, it is necessary to assess effect of humidity for all torque stages le with the procedure specified []. This assessment is not reflected this report. The graphs showg the change of temperature and humidity durg calibration of the comparison standard by the participants (blue graph temperature, green graph humidity) are given Figures 4, 5, and 6. Figure 4 Graph of temperature and humidity change durg calibration of the comparison standard (U1), Left: clockwise torque, Right: anti-clockwise torque

5 Figure 5 Graph of temperature and humidity change durg calibration of the comparison standard (Р), Left: clockwise torque, Right: anti-clockwise torque Figure 6 Graph of temperature and humidity change durg calibration of the comparison standard (U3), Left: clockwise torque, Right: anti-clockwise torque 6 Measurement results The measurement results are given Table 5. Table 5 Measurement results Torque Mean readgs UNIIM1 UNIIM3 Relative deviation Relative Relative Relative Mean Mean UNIIM1 - standard standard standard readgs readgs uncertaty taty taty uncer- uncer- Clockwise torque Relative deviation UNIIM Anti-clockwise torque The measurement results from Table 5 are illustrated by Figures 7 and 8.

6 Figure 7 Deviation of UNIIM1 mean readgs from РТВ and relative standard uncertaties of UNIIM1 and РТВ, Left: clockwise torque, Right: anti-clockwise torque Figure 8 Deviations of UNIIM3 mean readgs from РТВ and relative standard uncertaties of UNIIM3 and РТВ, Left: clockwise torque, Right: anti-clockwise torque 7 Assessment of supplementary comparison data The supplementary comparison data were evaluated agast the Е n equivalence criterion. Accordg to the collected data le with [3] the followg values have been calculated: reference values for UNIIM1 and for UNIIM3 accordg to (1) x n i1 ref n i1 u x i u xi 1 standard uncertaty of reference values accordg to () equivalence criterion Е n accordg to (3) E n u x ref n i1 x i 1 1 u x i x u ref ; (1) ; xi xref. (3) u x i ()

7 The results of the reference values calculations, the standard uncertaties of the reference values, and the equivalence criterion are provided Table 6. Table 6 Results of calculations of reference values, standard uncertaties of reference values, equivalence criterion Torque Reference value UNIIM1 - Standard uncertaty of the reference value nv/v Equivalence criterion Е n Clockwise torque Reference value UNIIM3 - Standard uncertaty of the reference value nv/v Equivalence criterion Е n Anti-clockwise torque Furthermore, the assessment of the supplementary comparison data has been conducted le with Pearson's chi-squared test (χ ). The fdgs and conclusions are given Annex A. 8 Conclusions The maximum value of the calculated equivalence criterion does not exceed specified value, equal to 1, which confirms that data collected by UNIIM durg comparisons can be recognized as confirmg stated uncertaty of the standard mache ЭУ-500. REFERENCES [1] D. Röske, K. Ogushi, Fal Report on the Torque Key Comparison CCM.T-K. Measurand Torque: 0 k, 10 k, 0 k, Metrologia, 016, 53, Tech. Suppl., 07008, [] D. Röske, Fal report on the torque key comparison CCM.T-K1. Measurand torque: 0, 500, 1000, Metrologia, 009, 46, Tech. Suppl., 0700, [3] R/GM/19:008 Guidele on COOMET supplementary comparison evaluation. COOMET Recommendation

8 Annex A Assessment of supplementary comparison data le with Pearson's chisquared test (χ ) In accordance with the requirements specified [3], check of comparison data consistency is conducted based on measurement results and pertent uncertaties, provided by the participants of comparisons. Value of the Pearson's chi-squared test χ is calculated accordg to (4) n xi xref. (4) i1 u xi In this case the reference value for comparisons is not calculated, and the readgs of, as the NMI-pilot of key comparisons, are adopted as the reference value. The results of the Pearson's chi-squared test calculations are given the Table A1 Table A1 Pearson's chi-squared test results Torque Pearson's chisquared test results (χ ) UNIIM1 from РТВ Torque Pearson's chisquared test results (χ ) UNIIM3 from РТВ Torque Pearson's chisquared test results (χ ) Torque Pearson's chisquared test results (χ ) Conclusions 1. Critical value of χ for the level of confidence 0.95 and the number of degrees of freedom n-1, equal to 1, is Calculated values of χ test for given conditions do not exceed the critical value and this shows, that obtaed results of the comparisons may be recognized as consistent, which confirms the stated uncertaties of the standard mache ЭУ-500.