Measurement Uncertainty


Book Description

Literally an entire course between two covers, Measurement Uncertainty: Methods and Applications, Fourth Edition, presents engineering students with a comprehensive tutorial of measurement uncertainty methods in a logically categorized and readily utilized format. The new uncertainty technologies embodied in both U.S. and international standards have been incorporated into this text with a view toward understanding the strengths and weaknesses of both. The book is designed to also serve as a practical desk reference in situations that commonly confront an experimenter. The text presents the basics of the measurement uncertainty model, non-symmetrical systematic standard uncertainties, random standard uncertainties, the use of correlation, curve-fitting problems, and probability plotting, combining results from different test methods, calibration errors, and uncertainty propagation for both independent and dependent error sources. The author draws on years of experience in industry to direct special attention to the problem of developing confidence in uncertainty analysis results and using measurement uncertainty to select instrumentation systems.




Calibration Handbook of Measuring Instruments


Book Description

Calibration Handbook of Measuring Instruments is mainly written for operators involved in verifying and calibrating measuring instruments used in Quality Management Systems ISO 9001, Environment Applications ISO 14001, Automotive Industry ISO 16949, and Aviation Industry EN 9100. It is a handy reference and consultation handbook that covers useful topics on assuring and managing industrial process measurement, such as: -The general concepts for managing measurement equipment according to the ISO 10012 concerning the management system of instruments and measurements -An instrument's suitability to perform accurate measurements and control the drift to maintain the quality of the measurement process -The criteria and procedures for accepting, managing, and verifying the calibration of the main industrial measuring instruments -The provisions of law and regulations for production, European marking CE of metrological instruments used in commercial transaction and for their periodic verification Report templates that are useful for recording both the recorded instrument data and the experimental calibration data and evaluating the conformity of the instrument, are available on a CD for practical use. The CD also contains various spreadsheets in Excel, Reports Calibration, which automatically calculate errors and the relative measurement uncertainty for determining a calibrated instrument's compliance.




Calibration


Book Description

This comprehensive review of calibration provides an excellent foundation for understanding principles and applications of the most frequently performed tasks of a technician. Topics addressed include terminology, bench vs. field calibration, loop vs. individual instrument calibration, instrument classification systems, documentation, and specific calibration techniques for temperature, pressure, level, flow, final control, and analytical instrumentation. The book is designed as a structured learning tool with questions and answers in each chapter. An extensive appendix containing sample P&IDs, loop diagrams, spec sheets, sample calibration procedures, and conversion and reference tables serves as very useful reference. If you calibrate instruments or supervise someone that does, then you need this book.




Measurement Uncertainties


Book Description

This book fulfills the global need to evaluate measurement results along with the associated uncertainty. In the book, together with the details of uncertainty calculations for many physical parameters, probability distributions and their properties are discussed. Definitions of various terms are given and will help the practicing metrologists to grasp the subject. The book helps to establish international standards for the evaluation of the quality of raw data obtained from various laboratories for interpreting the results of various national metrology institutes in an international inter-comparisons. For the routine calibration of instruments, a new idea for the use of pooled variance is introduced. The uncertainty calculations are explained for (i) independent linear inputs, (ii) non-linear inputs and (iii) correlated inputs. The merits and limitations of the Guide to the Expression of Uncertainty in Measurement (GUM) are discussed. Monte Carlo methods for the derivation of the output distribution from the input distributions are introduced. The Bayesian alternative for calculation of expanded uncertainty is included. A large number of numerical examples is included.




Uncertainty Analysis for Engineers and Scientists


Book Description

Build the skills for determining appropriate error limits for quantities that matter with this essential toolkit. Understand how to handle a complete project and how uncertainty enters into various steps. Provides a systematic, worksheet-based process to determine error limits on measured quantities, and all likely sources of uncertainty are explored, measured or estimated. Features instructions on how to carry out error analysis using Excel and MATLAB®, making previously tedious calculations easy. Whether you are new to the sciences or an experienced engineer, this useful resource provides a practical approach to performing error analysis. Suitable as a text for a junior or senior level laboratory course in aerospace, chemical and mechanical engineering, and for professionals.




Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results (rev. Ed. )


Book Description

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.




Uncertainty Analysis of Instrument Calibration and Application


Book Description

Experimental aerodynamic researchers require estimated precision and bias uncertainties of measured physical quantities, typically at 95 percent confidence levels. Uncertainties of final computed aerodynamic parameters are obtained by propagation of individual measurement uncertainties through the defining functional expressions. In this paper, rigorous mathematical techniques are extended to determine precision and bias uncertainties of any instrument-sensor system. Through this analysis, instrument uncertainties determined through calibration are now expressed as functions of the corresponding measurement for linear and nonlinear univariate and multivariate processes. Treatment of correlated measurement precision error is developed. During laboratory calibration, calibration standard uncertainties are assumed to be an order of magnitude less than those of the instrument being calibrated. Often calibration standards do not satisfy this assumption. This paper applies rigorous statistical methods for inclusion of calibration standard uncertainty and covariance due to the order of their application. The effects of mathematical modeling error on calibration bias uncertainty are quantified. The effects of experimental design on uncertainty are analyzed. The importance of replication is emphasized, techniques for estimation of both bias and precision uncertainties using replication are developed. Statistical tests for stationarity of calibration parameters over time are obtained.Tripp, John S. and Tcheng, PingLangley Research CenterBIAS; PRECISION; ERRORS; CALIBRATING; CONFIDENCE LIMITS; MATHEMATICAL MODELS; STATISTICAL ANALYSIS; STATISTICAL TESTS; REGRESSION ANALYSIS; LEAST SQUARES METHOD







Measurement and Instrumentation


Book Description

Measurement and Instrumentation: Theory and Application, Second Edition, introduces undergraduate engineering students to measurement principles and the range of sensors and instruments used for measuring physical variables. This updated edition provides new coverage of the latest developments in measurement technologies, including smart sensors, intelligent instruments, microsensors, digital recorders, displays, and interfaces, also featuring chapters on data acquisition and signal processing with LabVIEW from Dr. Reza Langari. Written clearly and comprehensively, this text provides students and recently graduated engineers with the knowledge and tools to design and build measurement systems for virtually any engineering application. - Provides early coverage of measurement system design to facilitate a better framework for understanding the importance of studying measurement and instrumentation - Covers the latest developments in measurement technologies, including smart sensors, intelligent instruments, microsensors, digital recorders, displays, and interfaces - Includes significant material on data acquisition and signal processing with LabVIEW - Extensive coverage of measurement uncertainty aids students' ability to determine the accuracy of instruments and measurement systems