Results of measurements and conclusions derived from them constitute much of the technical information produced by the National Institute of Standards and Technology (NIST). In July 1992 the Director of NIST appointed an Ad Hoc Committee on Uncertainty Statements and charged it with recommending a policy on this important topic. The Committee concluded that the CIPM approach could be used to provide quantitative expression of measurement that would satisfy NIST¿s customers¿ requirements. NIST initially published a Technical Note on this issue in Jan. 1993. This 1994 edition addresses the most important questions raised by recipients concerning some of the points it addressed and some it did not. Illustrations.
Results of measurements and conclusions derived from them constitute much of the technical information produced by NIST. It is generally agreed that the usefulness of measurement results, and thus much of the information that we provide as an institution, is to a large extent determined by the quality of the statements of uncertainty that accompany them. For example, only if quantitative and thoroughly documented statements of uncertainty accompany the results of NIST calibrations can the users of our calibration services establish their level of traceability to the U.S. standards of measurement maintained at NIST.
Reports NIST research and development in the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Emphasis on measurement methodology and the basic technology underlying standardization.
This handbook is a both a description of the current practice at the National Institute of Standards and Technology, and a compilation of the theory and lore of gauge block calibration. Most of the chapters are nearly self-contained so that the interested reader can, for example, get information on the cleaning and handling of gauge blocks without having to read the chapters on measurement schemes or process control, etc. This partitioning of the material has led to some unavoidable repetition of material between chapters. The basic structure of the handbook is from the theoretical to the practical. Chapter 1: basic concepts and definitions of length and units; Chapter 2: history of gauge blocks, appropriate definitions and a discussion of pertinent national and international standards; Chapter 3: physical characteristics of gauge blocks, including thermal, mechanical and optical properties; Chapter 4: a description of statistical process control (SPC) and measurement assurance (MA) concepts; and Chapters 5 and 6: details of the mechanical comparisons and interferometric techniques used for gauge block calibrations. Full discussions of the related uncertainties and corrections are included. Finally, the appendices cover in more detail some important topics in metrology and gauge block calibration.
Alcohol, Drugs, and Impaired Driving addresses many theoretical and practical issues related to the role played by alcohol and other psychoactive drugs on driving performance, road-traffic safety, and public health. Several key forensic issues are involved in the enforcement of laws regulating driving under the influence of alcohol and/or other drugs, including analytical toxicology, pharmacology of drug action, as well as the relationships between dose taken, concentration levels in the body, and impairment of performance and behavior. Our knowledge of drunken driving is much more comprehensive than drugged driving, so a large part of this book is devoted to alcohol impairment, as well as impairment caused by use of drugs other than alcohol. For convenience, the book is divided into four main sections. The first section gives some historical background about measuring alcohol in blood and breath as evidence for the prosecution of traffic offenders. The important role of the Breathalyzer instrument in traffic-law enforcement, especially in Australia, Canada, and the USA is presented along with a biographical sketch of its inventor (Professor Robert F. Borkenstein of Indiana University) with focus on the man, his work and his impact. The second section discusses several issues related to forensic blood and breath-alcohol alcohol analysis as evidence for prosecution of traffic offenders. This includes how the results should be interpreted in relation to impairment and an evaluation of common defense challenges. Because most countries have adopted concentration per se laws, the main thrust of the prosecution case is the suspect’s measured blood- or breath-alcohol concentration. This legal framework necessitates that the analytical methods used are "fit for purpose" and are subjected to rigorous quality assurance procedures. The third section gives a broad overview of the current state of knowledge about driving under the influence of non-alcohol drugs in various countries. This includes adoption of zero-tolerance laws, concentration per se statutes, and clinical evidence of driver impairment based on field sobriety tests and drug recognition expert evidence. The fourth section deals with epidemiology, enforcement, and countermeasures aimed at reducing the threat of drunken and drugged driving. All articles have appeared previously in the international journal Forensic Science Review, but all are completely updated with current data, references, and the latest research on developments since the articles were published. This book contains a convenient collection of the best articles covering recommendations for blood and breath testing methods, public policy relating to such methods, and forensic and legal implications of the enforcement of measures to counter driving under the influence.
