Nitin K Mandavgade, S B Jaju, R R Lakhe
(Mechanical Engineering Department, Priyadarshni College of Engineering, Nagpur 440019, India)
Abstract：The overall purpose of performing measurements in science is to increase knowledge and document about some physical quantity. The measurand has a true value but, except for straightforward counting situations, the true value can never be fully determined. When a quantity is measured, the outcome depends on the measuring system, the measurement procedure, the skill of the operator, the environment and other effects. In practice the uncertainty on the result may arise from many possible sources, including examples such as incomplete definition, sampling, matrix effects and interferences, environmental conditions, uncertainties of weights and volumetric equipment, reference values, approximations and assumptions incorporated in the measurement method and procedure, and random variation. The objective of the paper is how to identify the sources of uncertainty in measurement and their importance on the result.
Key words：measurement; error; true value; uncertainty; cause and effects analysis; sources; questioner
CLD number： TP274 Document code： A
Article ID： 1674-8042(2012)04-0307-06 doi： 10.3969/j.issn.1674-8042.2012.04.001
References
[1] Doiron T， Stoup J. Uncertainty and dimensional calibrations. Journal of Research of the National Institute of Standards and Technology, 1997,102(6):647-676.
[2] ISO/CASCO.ISO/IEC 17025:1999—general requirements for the competence of calibration and testing laboratories. ISO, Geneva, 1999.
[3] Guide to the expression of uncertainty in measurement. ISO, Geneva, Switzerland, 1993.
[4] Mandavgade N K, Jaju S B, Lakhe R R. Determination of uncertainty in gross calorific value of coal using bomb calorimeter. International Journal of Measurement Technologies and Instrumentation Engineering, 2011, 1(4), 45-52.
[5] Ellison S L R, Rosslein M, Williams A. EURACHEM/CITAC guide CG4—quantifying uncertainty in analytical measurement. 2nd Editon. EURACHEM/CITAC, London, 1995.
[6] EURACHEM Working Group, The fitness for purpose of analytical methods-a laboratory guide to method validation and related topics. [s.n.], 1998.
[7] ISO. International vocabulary of basic and general standard terms in metrology(VIM). ISO, Geneva, Switzerland, 1993.
[8] Analytical Methods Committee. Analyst, 1995: 120(1): 29-34.
[9] ISO/IEC Guide 33:1989—Uses of certified reference materials. ISO, Geneva, 1989.
[10] Good I J. Degree of belief // Kotz S, Johnson S L, Read C. Encyclopaedia of Statistical Sciences. John Wiley & Sons Inc, 1982.
[11] Kragten J. Calculating standard deviations and confidence intervals with a universally applicable spreadsheet technique.Analyst,1994, 119: 2161-2166.
