Marija Cundeva-Blajer
OPTIMIZATION METHODS IN METROLOGY OF ELECTRICAL QUANTITIES

In electrical quantities metrology numerous examples of stochastic processes exist and a need for optimal solutions is posed. Here stochastic genetic algorithm optimization is used for solving two typical metrological problems: errors minimization in process of instrument’s design and predicting metrological reference standards time-drift. The first case is optimal metrological design of a combined instrument transformer and the second case is analysis of resistance standard time-drift.

Robert Schmitt, Tobias Fürtjes, Walter Kimmelmann, Philipp Kosse, Andrea Buratti
QUALITY MONITORING IN MASS PRODUCTION OF MULTIAXIAL NON-CRIMP FABRICS BY USING A MULTISENSOR SYSTEM

Due to their excellent mechanical properties and light weight, fiber-reinforced plastic (FRP) has a huge potential as a way to reduce vehicle and airplane weight and is therefore a subject of interest for aerospace and automotive industries. To mass-produce FRP products, certain textile structures are commonly used as semifinished products, such as multiaxial non-crimp fabrics (NCF). Currently, there is no automated monitoring system capable of ensuring quality in NCF production. The purpose of this study is to develop tools and concepts that could lead to fully-automated quality control of non-crimp fabrics. Useful sensor concepts were developed based on a thorough requirement analysis. Sensor data fusion strategies were conceived and evaluated to combine image processing information and basis weight sensor information with the purpose of detecting relevant quality features in a textile sample. The developed algorithm was tested on a textile sample and a corresponding defect map was generated. Results showed that it is possible to identify common textile defect types by combining these two sensors.

Rossella Berni, Carlo Carobbi
ALTERNATIVE STATISTICAL ANALYSIS OF INTERLABORATORY COMPARISON MEASUREMENT RESULTS

Measurement results provided by laboratories involved in interlaboratory comparisons are processed in order to obtain the reference value of the quantity under measurement and its uncertainty. Measurement results are also compared with the reference value and its uncertainty in order to assess participants performance. Standards procedures are available in order to statistically process the measured values resulting from interlaboratory comparisons, such as those described in [1]. Unfortunately these procedures do not take into account the measurement uncertainty that each participant is required to declare. Well established statistical methods, such as errors measurement models, are however available that permit to statistically process both the measured values and their uncertainty, and therefore to fully evaluate the dispersion effects involved in the interlaboratory comparison activity.

Jiri Vyroubal, Martin Kolar, Viktor Bubla
MACHINE TOOLS ENERGY CONSUMPTION MEASUREMENT DEVICES

Measurement of energy consumption of machine tool is a fundamental step for improving the energy efficiency during production. Machine tool is a very complex product which need specific measuring devices for both types of energy usage during machining – electric and pneumatic. These devices, used in shop floor, should be robust and reliable. Several developed devices are presented to make a proper measurement of energy including PLC monitoring as a possible sensorless diagnostic.

Carlo Marinari, Fabio Saba, Marina Orio
THE INRIM THERMAL ENERGY STANDARD

In 2009, INRIM opened a research activity to plan the design and the realization of an innovative Thermal Energy Standard. The paper presents the main features of the new national standard and the innovative measurement approach adopted in order to faithfully simulate the real operating conditions of direct heat meters. An overview of the measurement procedure and the first experimental results for assessing the metrological performances of the thermal energy standard are given.