This 2nd edition volume of Modern Gas-Based Temperature and Pressure Measurements follows the first publication in 1992. It collects a much larger set of information, reference data, and bibliography in temperature and pressure metrology of gaseous substances, including the physical-chemical issues related to gaseous substances. The book provides solutions to practical applications where gases are used in different thermodynamic conditions. Modern Gas-Based Temperature and Pressure Measurements, 2nd edition is the only comprehensive survey of methods for pressure measurement in gaseous media used in the medium-to-low pressure range closely connected with thermometry. It assembles current information on thermometry and manometry that involve the use of gaseous substances which are likely to be valid methods for the future. As such, it is an important resource for the researcher. This edition is updated through the very latest scientific and technical developments of gas-based temperature and pressure measurements using thermometry and manometry, and brings all of the techniques together under one cover. This book fills the gap in international literature, as no other recently published book provides a comprehensive survey for gaseous media closely connected with thermometry. Updates in this new edition include revised appendices and new chapters on Mutual Recognition Agreement of the Comité International des Poids et Mesures and its main applications, and developments in the European Metrology Society.

Based on The International Metrology Congress meeting, this reference examines the evolution of metrology, and its applications in industry, environment and safety, health and medicine, economy and quality, and new information and communication technologies; details the improvement of measurement procedures to guarantee the quality of products and processes; and discusses the development of metrology linked to innovating technologies. The themes of the Congress (quality and reliability of measurement, measurement uncertainties, calibration, verification, accreditation, sensory metrology, regulations and legal metrology) are developed either in a general way or applied to a specific economic sector or to a specific scientific field.

This book delivers a comprehensive overview of units of measurement. Beginning with a historical look at metrology in Ancient India, the book explains fundamental concepts in metrology such as basic, derived and dimensionless quantities, and introduces the concept of quantity calculus. It discusses and critically examines various three and four-dimensional systems of units used both presently and in the past, while explaining why only four base units are needed for a system of measurement. It discusses the Metre Convention as well as the creation of the International Bureau of Weights and Measures, and gives a detailed look at the evolution of the current SI base units of time, length, mass, electric current, temperature, intensity of illumination and substance. This updated second edition is extended with timely new chapters discussing past efforts to redefine the SI base units as well as the most recent 2019 redefinitions based entirely on the speed of light and other fundamental physical constants. Additionally, it provides biographical presentations of many of the historical figures behind commonly used units of measurements, such as Newton, Joule and Ohm, With its accessible and comprehensive treatment of the field, together with its unique presentation of the underlying history, this book is well suited to any student and researcher interested in the practical and historical aspects of the field of metrology.

The first two chapters of this book are an update and outgrowth of the monograph Nonequilibrium Phenomena in Polyatomic Gases published by OUP in 1990, and a response to considerable improvements in the experimental determination of the transport properties of dilute gases that have taken place during the past 30 years. The experimental determination has improved sufficiently that it has become necessary to carry out calculations at the level of the second Chapman-Cowling approximation in order to give computed results that lie within the current experimental uncertainties now being reported. Chapter 3 is devoted to realistic interatomic potential energy functions, and begins with a discussion of the need for more accurate representations of these functions. Direct inversion of both microscopic data (spectroscopic transition frequencies and atomic beam scattering) and bulk property data (pressure and acoustic second virial coefficients, transport properties) are discussed in detail. The quantum chemical ab initio determination of binary atomic interaction energies and their analytical representation are discussed, followed by a detailed considerations of the interaction energies between pairs of noble gas atoms. Chapter 4 is concerned with connections between theory and experiment, including a detailed discussion of pure noble gases and their binary mixtures. Chapter 5 focuses on how to obtain the spectroscopic and thermophysical properties of a specific molecular system theoretically step by step, and provides a reference for the specific theoretical calculation work.

This volume can be justified by the following three facts, the need to provide, from time to time, a co-ordinated set of lectures which present the relevant progress in Metrology, the increasing intertwining between Fundamental Physics and the practice of Metrological Measurements, and, third, the flurry of new and unexpected discoveries in this field, with a correlated series of Nobel Prizes bestowed to individuals working in Fundamental Constants research and novel experimental methods. One of the most fascinating and exciting characteristics of metrology is its intimate relationship between fundamental physics and the leading edge of technology which is needed to perform advanced and challenging experiments and measurements, as well as the determination of the values and interrelations between the Fundamental Constants. In some cases, such as the caesium fountains clocks or the optical frequency standards, the definition of the value of a quantity is, in the laboratory, in the region of 10-16 and experiments are under way to reach 10-18. Many of these results and the avenues leading to further advances are discussed in this volume, along a major step in metrology, expected in the near future, which could change the “old” definition of the kilogram, still based on a mechanical artefact, toward a new definition resting on a fixed value of a fundamental constant.