In this article we gave an overview of vision-based measurement (VBM), its various components, and uncertainty in the correct IM (instrumentation and measurement) metrological perspective. VBM is a fast rising technology due to the increasing affordability and capability of camera and computing hardware/software. While originally a specialized application, VBM is expected to become more ubiquitous in our everyday lives as apparent from the applications described in this article.

The good measurement practice requires that the measurement uncertainty is estimated and provided together with the measurement result. The practice today, which is reflected in the reference standard provided by the IEC-ISO "Guide to the expression of uncertainty in measurement," adopts a statistical approach for the expression and estimation of the uncertainty, since the probability theory is the most known and used mathematical tool to deal with distributions of values. However, the probability theory is not the only tool to deal with distributions of values and is not the most suitable one when the values do not distribute in a totally random way. In this case, a more general theory, the theory of the evidence, should be considered. This paper recalls the fundamentals of the theory of the evidence and frames the random-fuzzy variables within this theory, showing how they can usefully be employed to represent the result of a measurement together with its associated uncertainty. The mathematics is defined on the random-fuzzy variables, so that the uncertainty can be processed, and simple examples are given.

The problem of evaluating power-quality is becoming an impelling need due to the proliferation of disturbing loads in the electric power systems. Unfortunately, the identification of the sources disturbing the system cannot generally be achieved by means of measurements in a single metering section of the electric network. This paper proposes a distributed measuring system to monitor a number of power-quality indices on every load connected to the same point of common coupling, to transmit the measured values to a master device that processes them in order to locate the sources of unbalance and harmonic distortion and to quantify the effects of such disturbances on power quality. The results of some experimental work performed on a low-voltage network are also reported.

Evolution and cost of measurement equipment, continuous training, and distance learning make it difficult to provide a complete set of updated workbenches to every student. For a preliminary familiarization and experimentation with instrumentation and measurement procedures, the use of virtual equipment is often considered more than sufficient from the didactic point of view, while the hands-on approach with real instrumentation and measurement systems still remains necessary to complete and refine the student's practical expertise. Creation and distribution of workbenches in networked computer laboratories therefore becomes attractive and convenient. This paper describes specification and design of a geographically distributed system based on commercially standard component