Mathematical modelling of metrological traceability chains

Abstract

Metrological traceability is a property of the measurement result and requires an established multi-level calibration hierarchy. The metrological traceability chain is established through the calibration hierarchy and is used to establish the metrological traceability of the measurement result. Approaches to the establishment of metrological traceability chains are based mainly on graphic images. Special international guidelines and European recommendations on the measurement uncertainty are used to evaluate the measurement uncertainty during the calibration of measuring instruments. The measurement uncertainty necessarily increases along the calibration sequence and is different for different levels of the metrological traceability chain. The measurement uncertainty depends on measurement standards or measuring instruments used during calibration. A mathematical model of the metrological traceability chain for different levels of the calibration hierarchy is proposed. This model includes, as components, such basic metrological characteristics for a certain level of the chain as the measurement range, measurement uncertainty, measuring instrument or measurement standard. As additional parameters for the metrological traceability chain, it is proposed to use data from the calibration certificate of the corresponding measuring instrument or measurement standard used at a certain level of the chain. Recommendations regarding practical application of the developed mathematical model of the metrological traceability chain, which can be used for chains of any measurements, are proposed. They can be used to establish the required metrological characteristics for a certain level of the metrological traceability chain. Such a model and recommendations for its practical application can be used in national metrology institutes and calibration laboratories.