ISO 4268:2000 石油および液体石油製品—温度測定—手動による方法 | 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.

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.

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

International Standard ISO 4268 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 3, Static petroleum measurement.

Introduction

In all calculations concerned with the measurement of bulk quantities of petroleum and petroleum products, whether in terms of volume at standard temperature or in terms of mass or apparent mass-in-air, a knowledge of the mean temperature of the oil is required. The following recommendations for the determination of the temperature of the contents of storage tanks, including tanks carried by road and rail vehicles and compartments of barges and ships, are designed to provide the most reliable measurement of the mean temperature under the given conditions.

It cannot be too strongly emphasized that errors in temperature measurement can account for the larger part of the total error in quantitative measurement of petroleum and liquid petroleum products, and great care is therefore needed in the selection and use of temperature-measuring equipment. The methods specified should be followed in scrupulous detail if the final measurement is to have the smallest possible uncertainty.

Gaugers employed in temperature measurement should be fully trained and instructed in the application of the procedures of this International Standard. They should be instructed to report any deviations that are unavoidable.

1 Scope

This International Standard specifies methods, procedures and equipment for the manual measurement of the temperature of bulk quantities of petroleum and petroleum products in storage tanks.

The preferred method is to use a portable electronic thermometer as described in clause 7. Other methods included use permanently installed indicating thermometers of the spot-measurement type and temperature determination by sampling methods using cup-case thermometers, flushing-case thermometers, and thermometers within conventional tank samples taken in accordance with ISO 3170.

This International Standard excludes averaging thermometers forming part of an automatic gauging system. These are described in ISO 4266.

It is realized that, in many countries, some or all of the items covered by this International Standard are the subject of mandatory regulations imposed by the laws of those countries; such regulations must be rigorously observed. In cases of conflict between such mandatory regulations and this International Standard, the former prevails.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.