The measurement of the electrical energy and its billing for tax purpose are of great relevance. In the past a scarce attention was given to issues as the calibration and the traceability of the electrical energy meters (EEMs), so that, at least in Italy, more than 30 millions of EEMs operate and put a tariff without proper metrological characterization. This situation is caused by both the absence of specific laws and the high cost related to the traceability process. In this ambit, a new European Directive on measuring instruments (MID) was introduced in 2004 with the aim of providing a high level of metrological protection in order that any party affected can have confidence in the result of measurement. In Italy the MID was adopted by a legislative decree and imposed that: (i) each active EEM put into service has to be kept in test for a period for verifying its operating; (ii) after the test period, with positive result, the meter has to be calibrated at least twice in the year. The paper proposes a discussion about the issues of active EEM calibration and the analysis of requirements of the MID. Finally, the design of a device that may solve the problem of the traceability to national standards in easy and economic way is reported.

The 3D points of a surface can be calculated from images achieved from two CCD cameras using stereoscopic methods. Classical procedures based on matching algorithms give errors at the highly curved or stepped surfaces. In this paper, we present a method to achieve a very high precision of measurement for surfaces with steps or holes, using a 3D multibeam scanner laser.

In this paper, some critical issues concerning the measurement of radiated emissions of products in an electromagnetic compatibility test stage are dealt with. In particular, an approach is proposed to evaluate the adequacy of anechoic enclosures that do not fulfil the requirements regarding the normalized site attenuation (NSA) factor. The purpose is to suggest a test method that can be used in order to define a way to know the limits of the chamber in terms of the frequency response over some critical radiations. To this aim, a number of simulation analyses and experiments have been performed for two different elementary types of radiating circuits (electric dipole, magnetic loop). Investigations have also been made by varying the physical size of the antennas.

In the paper, the characterization of designed and implemented high-performance real-time power quality measuring instrument is discussed. After a description of the hardware, firmware, power quality analyzer software and USB based data transfer mode, the paper continues with the discussion on a set of preliminary performances tests. In particular a set of test based on dip measurement and Total Harmonic Distortion measurement have been made and will be reported.

The behaviour of the low and medium frequency environmental magnetic field meters is investigated with reference to the possible approaches that can be implemented to evaluate compliance with the field exposure limits. The investigation is carried out both numerically and experimentally, in presence of sinusoidal and distorted waveforms, which are produced by the systems for the generation of reference magnetic fields up to 100 kHz set up at the Istituto Nazionale di Ricerca Metrologica of Torino. The adoption of different methods in the evaluation of the compliance to the exposure prescription may lead to different or even apparently inconsistent evaluations, when operating in presence of both sinusoidal and nonsinusoidal fields. By taking into account the different meter characteristics and output quantities, suitable checks of the measuring instruments with complex magnetic field waveforms of known frequency spectrum should be performed by adopting specific measurement procedures.