GUM

Introduction

JCGM 100 series – Guides to the expression of uncertainty in measurement (GUM series)

Two people measuring the same product with the same ruler on different days would probably get different results. This could be because of factors such as a change in the room temperature (important for a metal ruler) or different eyesight capabilities.  The two measurements might be equivalent or not, depending upon their individual uncertainties.  This concept of uncertainty is a measure of the quality of a measurement and can be vital in many cases.  The JCGM/100 series of documents establishes general rules for evaluating and expressing uncertainty in measurement that can be followed at various levels of accuracy and in many fields — from the shop floor to fundamental research. Therefore, the principles of these Guides are intended to be applicable to a broad spectrum of measurements, including those required for:

  • maintaining quality control and quality assurance in production;
  • complying with and enforcing laws and regulations;
  • conducting basic research, and applied research and development, in science and engineering;
  • calibrating standards and instruments and performing tests throughout a national measurement system in order to achieve traceability to national standards;
  • developing, maintaining, and comparing international and national physical reference standards, including reference materials
  • other metrology-related aspects

The series consists of the following parts:

  • JCGM 100 – Evaluation of measurement data – Guide to the expression of uncertainty in measurement (ISO/IEC Guide 98-3)
  • JCGM 101 – Evaluation of measurement data – Supplement 1 to the "Guide to the expression of uncertainty in measurement" – Propagation of distributions using a Monte Carlo method (ISO/IEC Guide 98-3-1)
  • JCGM 104 – Evaluation of measurement data – An introduction to the "Guide to the expression of uncertainty in measurement" (ISO/IEC Guide 98-1)

(For the moment, only JCGM 100 is available in HTML ;
PDF versions of JCGM 100, 101 and 104 are available here)


The following parts are under preparation:

  • JCGM 102 – Evaluation of measurement data – Supplement 2 to the "Guide to the expression of uncertainty in measurement" – Models with any number of output quantities (ISO/IEC Guide 98-3-2)
  • JCGM 103 – Evaluation of measurement data – Supplement 3 to the "Guide to the expression of uncertainty in measurement" – Modelling (ISO/IEC Guide 98-3-3)
  • JCGM 105 – Evaluation of measurement data – Concepts and basic principles (ISO/IEC Guide 98-2)
  • JCGM 106 – Evaluation of measurement data – The role of measurement uncertainty in conformity assessment (ISO/IEC Guide 98-4)
  • JCGM 107 – Evaluation of measurement data – Applications of the least-squares method (ISO/IEC Guide 98-5)
BIPM - Bureau International des Poids et Mesures ILAC - International Laboratory Accreditation Cooperation OIML - Organisation Internationale de Métrologie Légale IEC - International Electrotechnical Commission IFCC - International Federation of Clinical Chemistry and Laboratory Medicine ISO - International Organization for Standardization IUPAP - International Union of Pure and Applied Physics IUPAC - International Union of Pure and Applied Chemistry
Last modified: 2011-04-12