ISO/IEC GUIDE 99:2007 pdf free.International vocabulary of metrology — Basic and general concepts and associated terms (VIM).
ISO/IEC Guide 99:2007 provides a set of definitions and associated terms, in English and French, for a system of basic and general concepts used in metrology, together with concept diagrams to demonstrate their relations. Additional information is given in the form of examples and notes under many definitions.
In general, a vocabulary is a “terrninological dictionary which contains designations and definitions from one or more specific subject fields” (ISO 1087-1:2000, 3.7.2). The present Vocabulary pertains to metrology, the science of measurement and its application”. It also covers the basic principles governing quantities and units. The field of quantities and units could be treated in many different ways. Clause 1 of this Vocabulary is one such treatment, and is based on the principles laid down in the various parts of ISO 31, Quantities and units, currently being replaced by ISO 80000 and IEC 80000 series Quantities and units, and in the SI Brochure, The International System of Units (published by the BIPM).
The second edition of the International vocabulaiy of basic and general terms in metrology (VIM) was published in 1993. The need to cover measurements in chemistry and laboratory medicine for the first time, as well as to incorporate concepts such as those that relate to metrological traceability, measurement uncertainty, and nominal properties, led to this third edition. Its title is now International vocabulary of met rology — Basic and general concepts and associated terms (VIM), in order to emphasize the primary role of concepts In developing a vocabulary.
In this Vocabulary, it is taken for granted that there Is no fundamental difference in the basic principles of measurement in physics, chemistry, laboratory medicine, biology, or engineering. Furthermore, an attempt has been made to meet conceptual needs of measurement in fields such as biochemistry, food science, forensic science, and molecular biology.
Several concepts that appeared in the second edition of the VIM do not appear in this third edition because they are no longer considered to be basic or general. For example, the concept response time’, used in describing the temporal behaviour of a measuring system, is not included. For concepts related to measurement devices that are not covered by this third edition of the VIM, the reader should consult other vocabularies such as IEC 60050, International Electrotechnical Vocabulary, 1EV. For concepts concerned with quality management, mutual recognition arrangements pertaining to metrology, or legal metrology, the reader is referred to documents given in the bibliography.
Development of this third edition of the VIM has raised some fundamental questions about different current philosophies and descriptions of measurement, as will be summarized below. These differences sometimes lead to difficulties in developing definitions that could be used across the different descriptions. No preference is given in this third edition to any of the particular approaches.
The change in the treatment of measurement uncertainty from an Error Approach (sometimes called Traditional Approach or True Value Approach) to an Uncertainty Approach necessitated reconsideration of some of the related concepts appearing in the second edition of the VIM. The objective of measurement in the Error Approach is to determine an estimate of the true value that is as close as possible to that single true value. The deviation from the true value is composed of random and systematic errors. The two kinds of errors, assumed to be always distinguishable. have to be treated differently. No rule can be derived on how they combine to form the total error of any given measurement result, usually taken as the estimate. Usually, only an upper limit of the absolute value of the total error is estimated, sometimes loosely named “uncertainty”.