COOMET TECHNICAL COMMITTEE 1.8 PHYSICAL CHEMISTRY. CООМЕТ project 576/RU/12

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1 COOMET TECHNICAL COMMITTEE 1.8 PHYSICAL CHEMISTRY CООМЕТ project 576/RU/12 SUPPLEMENTARY COMPARISON STANDARDS IN THE FIELD OF ANALYSIS OF GAS MIXTURES CONTAINING СО 2, СО, С 3 Н 8 IN NITROGEN ( AUTOMOTIVE GAS MIXTURES) - Protocol, August Background The relevance of the comparison is founded on tightening of requirements to a control of car exhaust gases (implementation of environmental standards Euro-4 and Euro-5). Foundation of the COOMET comparison: Recognition of national measurement standards of National Metrological Institutes and entering of calibration and measurement capabilities (CMC) to BIPM KCDB in accordance with the Mutual Recognition Arrangement (CIPM MRA) for national measurement standards and for calibration and measurement certificates issued by NMIs; Objective of NMIs which participated in comparisons of this type earlier is to support or improve their CMCs. Note - This comparison was planned as a key comparison. The Gas Ahalysis Working Group (GAWG CCQM) on its 30-th meeting in Pretoria decided to rename this comparison as a supplementary. 2. Participants VNIIM, Russia KazInMetr, Kazakhstan BelGim, Belarus Ukrmetrteststandart, Ukraine BAM, Germany 3. Subject of the study The subject of the study is gas mixtures of СО 2, СО, С 3 Н 8 in nitrogen ( automotive gas mixtures) in cylinders prepared gravimetrically at the Research Department for the State Measurement Standards in the Field of Physical-Chemical Measurements of VNIIM. The concentrations of components in gas mixtures lie within the following range: 1

2 Nitrogen 135 mmol/mol 30 mmol/mol 2.0 mmol/mol balance The concentration of the components in the gas mixtures is calculated according to the ISO 6142 from purity analyses and the gravimetry, with checking of composition by an analytical procedure. The reference values are assigned to each gas mixture on the base of the gravimetric preparation. Cylinders with volume 5 dm 3 and 9 dm 3 will be used for preparation gas mixtures СО 2, СО, С 3 Н 8 in nitrogen. The pressure in cylinders before the dispatch to participants will be approximately 8,0 MPa. 4. The task of the participants The participants should determine the value of mole fraction СО 2, СО, С 3 Н 8 in the received gas mixtures. There should be implemented three independent measurements obtained under repeatability conditions. The form of the measurement report is given in Annex 1. Participating laboratories should specify in detail which analytical method was applied, which calibration method was used, as well as the way in which the own calibration samples were prepared. Also the measurement report should contain the calculation of expanded uncertainty and the uncertainty budget. Measurement reports are sent in Word format using . After the measurements, cylinders with gas mixtures have to be returned to coordinating laboratory. Pressure in cylinders, before shipping to coordinating laboratory should be not less then 4,0 MPa, it is necessary for re-analysis at PCD of VNIIM. Participants should pay for the return of the cylinders to coordinating laboratory. 5. The responsibility of the coordinator VNIIM, as a coordinator will have to: - register of the comparison in the BIPM KCDB; - organize and pay for the shipment of the cylinders to participating laboratories; - be responsible for data collecting from participants and for the report developing; - correct the report according to marks of experts; - send preliminary and final reports to participating laboratories; - send the final report to COOMET and BIPM. 2

3 6. Time schedule of the comparison N пп 1 Content Preparation of gas mixtures in cylinders by the coordinating laboratory (VNIIM) September Stability research of prepared gas mixtures until November 15, Shipment of the cylinders to participants until December 15, Study of the gas mixtures by participants until February 28, Reports due to the coordinating laboratory until April 15, Cylinders due to the coordinating laboratory until April 30, Reanalysis of the gas mixtures by the coordinating laboratory until May 30, Draft А report July 2014 Coordinator of the key comparison: VNIIM, Leonid Konopelko Phone: Fax: lkonop@b10.vniim.ru Contact persons: VNIIM, Anna Kolobova Phone: Fax: VNIIM, Olga Efremova Phone: Fax: akol@b10.vniim.ru lkonop@b10.vniim.ru VNIIM, Alisa Orshanskaia Phone: Fax: lkonop@b10.vniim.ru 3

4 Annex 1 COOMET 576/RU/12) Key comparison of national standard in field of analysis gas mixtures containing СО2, СО, С3Н8 in nitrogen ( automotive gas mixtures) MEASUREMENT REPORT I. Results of study Laboratory: Cylinder number: Measurement 1 dd/mm/yy Result (mol/mol) Standard deviation (% relative) Number of sub measurements n Measurement 2 dd/mm/yy Result (mol/mol) Standard deviation (% relative) Number of sub measurements n 4

5 Measurement 3 dd/mm/yy Result (mol/mol) Standard deviation (% relative) Number of sub measurements n Note: Please copy this table as many times as needed for reporting additional measurements Final results: Result Assigned expanded Gas mixture (assigned value) Coverage factor uncertainty mol/mol mol/mol II. Description of study Instrument(s) Principles, make, type, configuration, data collection etc. Calibration Standards Calibration Standards for the measurements (preparation method, purity analyses. estimated uncertainty etc.) Instrument Calibration Calibration procedure (mathematical model/calibration curve, number and concentrations of standards, measurement sequence, temperature/pressure correction etc.) 5

6 Sample Handling How were the cylinders treated after arrival (e.g. stabilized) and how were samples transferred to the instrument? (automatic, high pressure, mass-flow controller, dilution etc) Uncertainty table: Uncertainty Estimate Assumed Standard Sensitivity Contribution to source x i distribution uncertainty coefficient standard X i u(x i ) c i uncertainty u i (y) Coverage factor: Expanded uncertainty: Optional You may provide additional data like the raw measurement data, information on your measurement procedure, chromatograms etc. 6