Luciano Brunetti, Luca Oberto, Emil Vremera
The power is the most important electromagnetic quantity from the metrological point of view, and for this reason the calibration techniques of high frequency power meters require a specific attention. Literature still refers to power meters of bolometer type, instruments that are mainly used almost only in the primary laboratories. Definitions, procedures, and calibration techniques elaborated for this instrument type must be adjusted before being applied to actual power meters, which work on different principles. Otherwise, inconsistent calibration results may be produced. This paper is...
XVIII IMEKO World Congress
· TC4
· 2006
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Hüseyin Çayci, Özlem Yilmaz, Burak Ayhan, Tansu Kefeli, Mustafa Günes, Erol Kazanç
A high accuracy power measurement system, based on digital sampling techniques, has been developed and evaluated for the power frequencies at UME (National Metrology Institute of Turkey). The system is based on two sampling voltmeters and a phase-locking device. Using of a precision voltage transformer and a current transformer with a shunt resistor, and reducing the synchronizing errors results in an uncertainty of 20 ppm for active, reactive and apparent power measurements for power frequencies.
XVIII IMEKO World Congress
· TC4
· 2006
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D.Gallo, C.Landi, N.Rignano
In the paper, the design and implementation of a high-performance real-time power quality measuring instrument based on digital signal processor (DSP) is discussed. After the hardware and firmware instrument description, the paper continues with the presentation of power quality analyzer software design and then is completed with metrological characterization of the instrument prototype, in terms of measurement accuracy and speed of execution.
XVIII IMEKO World Congress
· TC4
· 2006
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Lech Hasse, Lech Loroch, Krzysztof Rogala, Ludwik Spiralski
The noise (fluctuation) level and non-linear distortions can be established as a new criteria for selection of passive elements for different endurance (sustainability) and reliability groups. Measurement of third harmonic (TH) fluctuations and its implementation into the production testing system have been proposed. It can improve the process of quality estimation of high reliability elements.
XVIII IMEKO World Congress
· TC4
· 2006
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Martin Novotny, Milos Sedlacek
The paper analyses an effective method of increasing accuracy of active power measurement (and energy measurement) by non-coherent sampling. The measurement bias caused by non-coherent sampling are reduced by windowing the instantaneous power sequence of samples by various generalized cosine windows. Active power is found by processing signal in time domain, without using FFT. Newly obtained analytical formulae are given, a comparison to classical method and numerical simulations verifying the derived formulae are presented. A simple method of compensation multiplexing delay by measurement...
XVIII IMEKO World Congress
· TC4
· 2006
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A. Cataldo, L. Tarricone, M. Vallone, F. Attivissimo, A. Trotta
In a previous paper the Authors demonstrated that Time Domain Reflectometry (TDR) can be successfully used for an enhanced real-time qualitative and quantitative monitoring of liquids. In this paper, a metrological characterization of the method is formulated. Results are proposed, demonstrating the robustness and liability of the TDR technique.
XVIII IMEKO World Congress
· TC4
· 2006
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R. Queirós, R.C. Martins, P.S. Girão, A.Cruz Serra
This paper presents a new method for ultrasonic ranging. It consists on continuously transmitting a signal composed by multiple sine wave segments, each containing an integer number of periods. The frequency of each segment is different from the adjacent segments, but close to the transducer resonant frequency, to minimise the filtering effects of the system. The transmitted and received signals are cross-correlated to determine the time-of-flight (TOF). Parabolic interpolation on the cross-correlation’s magnitude is used to increase the accuracy of TOF estimation. High measurement...
XVIII IMEKO World Congress
· TC4
· 2006
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Hrvoje Hegeduš, Damir Ilic, Alan Šala
Two vehicle acceleration measurement methods for determination of time needed to achieve a velocity of 100 km/h are presented: a) based on the acceleration measurement with Analog Devices iMEMS accelerometers, b) based on a length measurement using signals from Antilock Braking System sensors. The measurements done in real conditions showed a very good agreement.
XVIII IMEKO World Congress
· TC4
· 2006
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A. Bernieri, L. D’Alessandro, M. Laracca, C. Liguori
Replacing a lamp in an outdoor installation, like roadway lighting, requires a lot of time and money. The proper maintenance strategy of installed lighting-system components is an essential element in ensuring that systems perform as designed and consequently ensure the safety. The paper presents a method for evaluating the residual life of High Pressure Sodium road lamps and for detecting incoming fault. The proposed method is based on the frequency domain analysis of the lamp current that changes its harmonic content in consequence of the aging.
XVIII IMEKO World Congress
· TC4
· 2006
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Christian Eugène, Michaël Demeyere
In the frame of a basic course on electrical measurements, a training session teaching the correct use of measuring instruments is presented. The context is that of a fluorescent tube, a non-linear device allowing interesting mathematical developments and measuring observations. In this session, the students are asked to evaluate the pertinence of dimming the lamp in terms of luminous efficiency and pollution of the mains.
XVIII IMEKO World Congress
· TC4
· 2006
· Download