Traceability model diagrams

The instrument model diagram consists in a visual sketch of the processing steps leading to a product and its traceability chain. Following the GAIA-CLIM Guidance note 'Guide to Uncertainty in Measurement & its Nomenclature' (final Version 4), the way to metrological robust uncertainty analysis and traceability chain starts from clearly displaying the whole process (main chain) in terms of three models: the physical, processing, and metrological (traceability) models. The physical model describes the physics behind each stage of the process that contributes to the measurements taken, including all of the physical processes associated with the measurand detection. The processing model considers how the raw data collected is processed to provide the end product, through calibration to final geophysical parameter. The metrological model describes the set of linkages of a measurement to a reference standard. The aim is to determine what the fundamental reference for the measurement is. The components used in the traceability chains (shown in the Figure) have been determined through consultation with the QA4ECV project.  The set used have been expanded from those used in QA4ECV to accommodate the differing needs of the GAIA-CLIM project.


Figure: The components used in the traceability chains produced under the GAIA-CLIM project.

 Model diagrams for the following measurement techniques have been produced by WP2: