This book discusses how and why historical measurement units developed, and reviews useful methods for making conversions as well as situations in which dimensional analysis can be used. It starts from the history of length measurement, which is one of the oldest measures used by humans. It highlights the importance of area measurement, briefly discussing the methods for determining areas mathematically and by measurement. The book continues on to detail the development of measures for volume, mass, weight, time, temperature, angle, electrical units, amounts of substances, and light intensity. The seven SI/metric base units are highlighted, as well as a number of other units that have historically been used as base units. Providing a comprehensive reference for interconversion among the commonly measured quantities in the different measurement systems with engineering accuracy, it also examines the relationships among base units in fields such as mechanical/thermal, electromagnetic and physical flow rates and fluxes using diagrams.

This book discusses how and why historical measurement units developed, and reviews useful methods for making conversions as well as situations in which dimensional analysis can be used. It starts from the history of length measurement, which is one of the oldest measures used by humans. It highlights the importance of area measurement, briefly discussing the methods for determining areas mathematically and by measurement. The book continues on to detail the development of measures for volume, mass, weight, time, temperature, angle, electrical units, amounts of substances, and light intensity. The seven SI/metric base units are highlighted, as well as a number of other units that have historically been used as base units. Providing a comprehensive reference for interconversion among the commonly measured quantities in the different measurement systems with engineering accuracy, it also examines the relationships among base units in fields such as mechanical/thermal, electromagnetic and physical flow rates and fluxes using diagrams.

It is for the first time that the subject of quantities and their respective units is dealt this much in detail, a glimpse of units of measurements of base quantities of length, time, mass and volume is given for ancient India, three and four dimensional systems of measurement units are critically examined, establishment of the fact that only four base units are needed to describe a system of units, the basics to arrive at the unit of a derived quantity are explained, basic, derived and dimensionless quantities including quantity calculus are introduced, life history of scientists concerned with measurements units are presented to be inspiring to working metrologists and students. The International System of Units including, Metre Convention Treaty and its various organs including International National of Weights and Measure are described. The realisation of base units is given in detail. Classes of derived units within the SI, units permitted for time to come, units outside SI but used in special fields of measurements are described. Methods to express large numbers are explained in detail. Multiples and sub-multiples prefixes and their proper use are also given. The latest trends to redefine the base Kilogram, Ampere, Kelvin and Mole on existing base units of mass, electric current, temperature and amount of substance, in terms of a single parameter or fundamental constants are briefly described.

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 History of Educational Measurement collects essays on the most important topics in educational testing, measurement, and psychometrics. Authored by the field’s top scholars, this book offers unique historical viewpoints, from origins to modern applications, of formal testing programs and mental measurement theories. Topics as varied as large-scale testing, validity, item-response theory, federal involvement, and notable assessment controversies complete a survey of the field’s greatest challenges and most important achievements. Graduate students, researchers, industry professionals, and other stakeholders will find this volume relevant for years to come.