Francesco Adamo, Filippo Attivissimo, Laura Fabbiano, Nicola Giaquinto, Maurizio Spadavecchia
In this paper the preliminary work of laboratory practices developed for didactic purposes for undergraduate courses at the Engineering Faculty of Polytechnic of Bari is presented. The educational purposes of these experiments can be summarized as follow: - to grant students the opportunity to verify theoretical arguments introduced in theoretical lessons; - to give technical skills; - to integrate research work and educational programs promoting the insertion of student in the scientific community. In this paper a technical solution useful to measure temperature by means of thermocouples is...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Francesco Adamo, Filippo Attivissimo, Attilio Di Nisio, Mario Savino
Today, computer vision inspection systems are widely used for quality control to reduce the costs and to improve the product quality. The glass industry is constantly trying to improve quality by substituting the human control with automated inspection systems but several problems must be solved. In this paper the problem of detecting and measuring the defects of satin glasses is investigated and a real-time system is proposed that is able to analyze the glass surface under inspection, to assess its quality and to characterize its defects. A prototype has been carefully designed and...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Giuseppe Cavone, Attilio Di Nisio, Nicola Giaquinto and Mario Savino
The paper illustrates a method for simultaneous ADC and DAC linearity testing in a loop-back scheme. The main features of the method are: (i) it is statistically nearly optimal, being based on a maximum likelihood estimator; (ii) it does not require prior knowledge neither of the ADC nonlinearity, nor of the DAC nonlinearity – both are simultaneously measured relying only on a constant-variance noise. The performances of the method are studied both mathematically and via computer simulations. The method, because of its optimality and universality, appears to be also a good candidate for...
M. Caciotta, F. Leccese, S. Pisa, E. Piuzzi
The need to correlate as accurately as possible Time to the power quality events pushes towards the necessity to develop circuits able to yield a time reference that is referable to International Time Standards. Moreover, the necessity to deploy distributed power quality monitoring systems requires these time references to be easy to disseminate, making them available on specific monitoring sites. In this paper, the possibility to obtain a time reference continuously traceable to a Cs133 atomic standard is proposed, by locking the Cesium-derived L1 GPS satellites carrier by means of a...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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P.P. Capra, C. Cassiago, F. Galliana, M. Astrua
A temperature variable high accuracy (TVHA) 10 kΩ resistor has been developed at National Institute of Metrological Research, (INRIM), in order to transfer the traceability to high accuracy multifunction instruments used in the accredited calibration laboratories. The TVHA consists of ten 100 kΩ nominal value resistors inserted in a copper block and connected in parallel configuration. The thermal stability of the copper block is obtained with a temperature controller. In this paper we reported details of the development of the TVHA and on its thermal behaviour. From preliminary results its...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Boleslaw Dudojc
In the paper the author refers to a common opinion about high immunity of current loop measurement and control line to interferences. That opinion is only theoretical. The author presents of some experiments results which are pointed out on limitations concern immunity to interferences especially to the two wire measurement line in 4-20 mA standard.
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Abraham Mejía-Aguilar, Ramon Pallàs-Areny
Impedance is the only electrical property common to all materials. Its measurement is used for material characterization and testing, and for sensor design. Impedance measurements in a broad frequency range are slow and need complex instrumentation. Impedance measurements in the time domain can be faster but need more computation power. We propose a novel measurement method intended for applications where the unknown impedance can be modeled by three independent components. The method consists of applying a single pulse, measuring three amplitudes, and calculating the unknown components from...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Nuno B. Brás, Raúl C. Martins, António C. Serra
Magnetic Induction Tomography (MIT) is an imaging technique for passive electrical properties used in industrial and biological imaging. In the case of biological purposes, high resolution measures of the magnetic field induced in the body and the ability to acquire data at several points along its border are two major challenges of MIT. In a previous work we have developed a prototype that allows precisely moving sensing and source coils, improving data quality and quantity for the tomographical image processing. Several alternatives for stability and resolution improvements have been...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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M. Dias Pereira, O. Postolache, P. Silva Girão
Two of the most important static transducer characteristics, in any measurement system, are linearity and accuracy. In the present paper the calibration and linearization of a low-cost orifice flow meter is considered. Accuracy improvements are based on calibration coefficients that are evaluated with the measurements obtained from a reference flow meter. Linearity improvement is based on a non-linear A/D conversion whose transfer characteristic is the inverse of the transducer’s characteristic. The linearity can be strongly improved using a non-linear A/D conversion performed by a low-cost...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Beata Pałczyńska
The paper considers applying the quadratic joint time – frequency transform for the spectral analysis of the non-stationary magnetic fields. The general properties, advantages and disadvantages of the quadratic algorithms from Cohen’s class like the short – time Fourier transform (STFT) spectrogram and the pseudo Wigner – Ville (PWV) distribution as well as the adaptive spectrogram are discussed. The selected results of the off-line time-frequency analysis of the recorded signals of magnetic field of ship bow thrusters drive with frequency converter are presented. Performed time-frequency...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
· Download