Traceability Issues in Distributed Measuring Systems

This paper deals with the traceability-assurance problems that are faced when a distributed measuring system is employed. These problems are highlighted for different distributed-system architecture, then a set of guidelines is provided in order to correctly manage such systems from a metrological point of view. The proposed solution is based on a network-assisted calibration procedure, which requires suitable travelling standards that are sent to the nodes of a distributed system under calibration and are remotely controlled through the Internet. Two prototypes of travelling standard are also described that have been designed in order to implement the proposed calibration procedure. The first prototype can be used for the calibration of system, which require tight temporal coherence, while the second one is able to calibrate measuring nodes that monitor the chemical pollution.