1. Method of Measurement Beam Machine Parameter Model Parameters Measurement System Beam Observable Physical Processes Instrument Influence Quantities Primary Observable Physical Process Sensor Influence Parameters Instrument Analog and Digital Processing + Corrections (Calibration, Sensor Model, other Parameter Influence…) Beam Observable Primary Observable Sensor Response

2. #! Precision & Stability !# Precision General concept to characterise the quality of an instrument. This word includes different notions (like accuracy or resolution) and should only be used in this view. We will for instance speak of document describing in details the accuracy and resolution as a document describing the precision of the instrument. Precision should not be used for accuracy or resolution. Stability General concept to characterise the behaviour in time of an instrument. This word includes the following two different notions: the repeatability and the reproducibility. Stability should not be used for repeatability or reproducibility.

3. Error vs Uncertainties Measured Value = True Value + Error True Value  Measured Value ± Uncertainty Under given Conditions

4. Uncertainties vs Accuracy While the uncertainty is a statistical quantity qualifying the precision of a class of measurements, the accuracy qualifies the demand on precision for the same measurements. When the uncertainty of the measurement is equal or lower than the tightest requirement on accuracy, the precision of the instrument is deemed satisfactory. We aim to: Uncertainty < Accuracy within given conditions

5. Terms Defined Accuracy - Exactitude Conditions - Conditions Correction - Correction Drift - Derive Dynamic Range - Gamme Dynamique Error - Erreur Random Error - Erreur Aleatoire Systematic Error - Erreur Systematique Influence Quantity - Grandeur d’Influence Instrument - Instrument Linear Coupling Factors - Facteurs de Couplage Lineaire. Measurand - Mesurande Measurement - Mesurage Measurement Device - Moyen de Mesure Measurement Method - Methode de Mesure Measurement System - Systeme de Mesure Noise - Bruit Non Linearity - Non Linearite Observable - Observable Primary/Beam Observable - Observable Primaire/Faisceau Offset - Piedestal Beam/Machine Parameter - Parametre Faisceau/Machine Precision - Precision Quantity - Grandeur Repeatability - Repetabilite Reproducibility - Reproducibilite Resolution - Resolution Response - Reponse Roll - Roulis Scaling Factor - Facteur d’Echelle Sensitivity - Sensibilite Sensor - Capteur Stability - Stabilite Trend - Tendance Uncertainty - Incertitude