ISO/TR 20461:2000 重量分析法を使用して行われた体積測定の不確かさの決定 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, 3.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful.

Attention is drawn to the possibility that some of the elements of ISO/TR 20461 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO/TR 20461 was prepared by Technical Committee ISO/TC 48, Laboratory glassware and related apparatus, Subcommittee SC 1, Volumetric instruments.

1 Scope

This Technical Report gives the detailed evaluation of uncertainty for volume measurements according to the Guide to the Expression of Uncertainty in Measurement (GUM) [1]. It uses the gravimetric method specified in ISO 8655-6[2] as the reference method for calibrating piston-operated volumetric apparatus. It has been arranged in paragraphs to facilitate direct access to different aspects of this kind of evaluation as follows:

• modelling the measurement by describing the physical equations necessary to calculate the volume using the gravimetric method of measurement;
• determination of the standard uncertainty of measurement associated with the volume V₂₀ by describing the calculation procedure according to the GUM;
• determination of the sensitivity coefficients with an example of the calculation of all sensitivity coefficients by using complete equations, approximations of equations and by giving numerical values for standard conditions;
• determination of the standard uncertainty associated with the volume delivered by a piston-operated volumetric apparatus giving the combination of the standard uncertainty associated with the volume V₂₀ measured using the gravimetric measuring system and the experimental standard deviation associated with the volume delivered by the apparatus;
• determination of the standard uncertainties of measurement with a brief insight into the calculation of uncertainties of measuring devices according to GUM;
• determination of the expanded uncertainty of measurement associated with volume V₂₀;
• example of the determination of the uncertainty for volume measurements.

Bibliography