POLISH ACADEMY OF SCIENCES

Division IV: Engineering Sciences

Committee on Metrology
and Scientific Instrumentation


VOLUME XV - NUMBER 1/2008 [previous] [next]

CONTENTS

Ewa Frączek, Janusz Mroczka - Influence of selected factors for localization accuracy in the Optical Vortex Interferometer3
Anatoliy A. Platonov, Łukasz M. Małkiewicz - Particularities of the cyclic A/D converters ENOB definition and measurement9
Lech Hasse, Janusz Smulko - Quality assessment of high voltage varistors by third harmonic index23
Salah Hamed Ramadan Ali - The influence of fitting algorithm and scanning speed on roundness error for 50 mm standard ring measurement using CMM33
Jadwiga Lal-Jadziak, Sergiusz Sienkowski - Models of bias of mean square value digital estimator for selected deterministic and random signals55
Krzysztof Duda - Lifting based compression algorithm for power system signals69
Witold Krieser - Positioning the sensor in sampling flowmeters85
Jakub Piwowarczyk, Krzysztof Pacholski - Utilization of Levenberg - Marquardt's method for identification of the electronic current transducer with a hall effect sensor in a feedback loop91
Adam Żuchowski - Analog dot recording as an exemplary problem in the area of dynamic measurements105
Igor P. Zakharov, Sergey V. Vodotyka - Application of Monte Carlo simulation for the evaluation of measurements uncertainty117
Stefan Medvecky - Prof. dr hab. inż. Stanisław Adamczak - Honoris Causa Doctorate, University of Zilina (Slovakia)125


ABSTRACTS & FULL PAPERS

p. 3 contents

EWA FRĄCZEK, JANUSZ MROCZKA

Wroclaw University of Technology
Chair of Electronic and Photonic Metrology
Poland, e-mail: ewa.fraczek@pwr.wroc.pl

INFLUENCE OF SELECTED FACTORS FOR LOCALIZATION ACCURACY IN THE OPTICAL VORTEX INTERFEROMETER

Optical vortices were intensively studied during the last decade. In the literature there are papers presenting applications of the optical vortices. The regular net of optical vortices generated by the three plane waves interference allows for the new kind of the interferometer - the Optical Vortex Interferometer (OVI). The precision of the OVI depends on the localization accuracy and the phase reconstruction. The localization methods lead to errors if we use beamsplitters with coatings changing the polarization state of the light. There are six beamsplitters used in this interferometer. In the setup we used non-polarizing coatings. We observed a pleochroism effect which occurs in these coatings. It is the cause of errors in the localization of optical vortices. In this paper we study the effect of pleochroism and we show the way to avoid errors in the localization of optical vortices in the OVI.

Keywords: optical vortices, interferometry

Full paper (228kB)
p. 9 contents

ANATOLIY A. PLATONOV, ŁUKASZ M. MAŁKIEWICZ

Warsaw University of Technology
Institute of Electronic Systems
Poland, e-mail: plat@ise.pw.edu.pl, L.Malkiewicz@elka.pw.edu.pl

PARTICULARITIES OF THE CYCLIC A/D CONVERTERS ENOB DEFINITION AND MEASUREMENT1,2

The paper is devoted to the methods of accurate assessment and analysis of the expected and actual effective number of bits (ENOB) of cyclic analog-to-digital converters. The equivalence of definition of ENOB in the IEEE Standard 1241-2000 and proposed in earlier author's works analytical definition formulated on the basis of distributions of the input signal and conversion errors. Indirect and direct methods of ENOB measurement are considered. The presented results can be used for a development of accurate methods of performance analysis and testing of the cyclic and other ADCs.

Keywords: analog-digital conversion, cyclic, intelligent ADC, ENOB, converter's performance

1 The work is supported by Grant 3 T11 059 29 of the Polish Ministry of Science and Information Society Technologies.
2 The work was presented at IEEE Instrumentation and Measurement Technology Conference (IMTC 2006) [5]

Full paper (560kB)
p. 23 contents

LECH HASSE, JANUSZ SMULKO

Gdańsk University of Technology
Faculty of Electronics, Telecommunication and Informatics
Department of Optoelectronics and Electronic Systems
Poland, e-mail: jsmulko@eti.pg.gda.pl


QUALITY ASSESSMENT OF HIGH VOLTAGE VARISTORS BY THIRD HARMONIC INDEX

High voltage varistors that consist mainly of grained ZnO have to be tested before assembling into a surge arrester. The existing methods demand a usage of high voltages and intensive currents that is inconvenient, destructive and needs extensive power consumption. Additionally, these methods require metallization of the prepared varistor structures that increases costs. We propose another method of varistor quality assessments by a third harmonic index measurement at relatively low voltage range. In this experimental study it has been proved that the proposed procedure can be applied successfully for preliminary selection of the tested structures.

Keywords: varistor, nonlinearity, quality assessment

Full paper (445kB)
p. 33 contents

SALAH HAMED RAMADAN ALI

National Institute of Standards (NIS)
Giza, Egypt
e-mail: Dr_Salah@nis.sci.eg

THE INFLUENCE OF FITTING ALGORITHM AND SCANNING SPEED ON ROUNDNESS ERROR FOR 50 mm STANDARD RING MEASUREMENT USING CMM

Coordinate Measuring Machines (CMM) become one of the main requirements in precision engineering for advanced industries, troubleshooting and scientific facilities. CMM data analysis software can contribute significantly to the total measurement errors. The error characteristics in the CMM software are very important from the metrological point of view to find an optimum fitting solution. The final accuracy of a work piece is influenced by many different factors.
In this paper, the fitting software methods and styles touch probe scanning speed factors for three different transverse circles of roundness measurement errors are studied experimentally and discussed in details. The tests have been performed to examine the problem of how to generate reference data sets for cylinder circle measurements. Some error formula have been postulated to correlate the roundness measurements within application range. These reference data sets are presented to help the CMM designer and operator to get the best fit for roundness measurements.

Keywords: precision engineering, CMM accuracy, fitting methods, roundness errors, probe scan speed

Full paper (6798kB)
p. 55 contents

JADWIGA LAL-JADZIAK1, SERGIUSZ SIENKOWSKI2

1 Nicolaus Copernicus University
Institute of Physics, Toruń, Poland
e-mail: jjadziak@fizyka.umk.pl
2 University of Zielona Góra
Institute of Electrical Metrology
Poland, e-mail: s.sienkowski@ime.uz.zgora.pl

MODELS OF BIAS OF MEAN SQUARE VALUE DIGITAL ESTIMATOR FOR SELECTED DETERMINISTIC AND RANDOM SIGNALS

The article presents the probability density functions as well as characteristic functions of selected periodic and random signals. On their basis, original models of the bias of the mean square value digital estimator have been designed. These models were employed in investigating estimation errors caused by analog to digital conversion and analog to digital conversion with a dither signal. Selected graphical model representations and their analyses are demonstrated.
It has been shown that for a triangular probability density function random signal with the amplitude At = kq, kN \ {0}, mean square value reconstruction occurs on the basis of a signal quantized with the accuracy of Sheppard's correction. Whereas for periodic signals as well as for the sum of periodic and random signals, the δ component of bias due to the nonsatisfaction of the reconstruction condition is a suppressed oscillating function of the quotient of the amplitude A and the quantization step size q.
It has been proved that by adding, prior to quantization, a triangular distribution random signal with zero mean and the amplitude At = kq (k = 1, 2, ...) in the mean square value measurement of any periodic signal, this bias component can be brought to zero.

Keywords: probability density function, characteristic function, Widrow's theory of quantization, mean square value, estimator bias

Full paper (2671kB)
p. 69 contents

KRZYSZTOF DUDA

AGH University of Science and Technology
Measurement & Instrumentation Department
Kraków, Poland
e-mail: kduda@agh.edu.pl

LIFTING BASED COMPRESSION ALGORITHM FOR POWER SYSTEM SIGNALS

The paper concerns the problem of power system signals compression with possible application in system monitoring and control. The proposed compression algorithm for power system signals ensures efficient use of available storage memory or communication channel bandwidth. It is shown that while preserving good quality, compression ratios from 20 in case of highly distorted waveforms to 340 for slightly distorted sinusoidal waves can be achieved. The presented results were evaluated with a specially prepared representative database of field-recorded electric signals. For signal decorrelation lifting implementation of wavelet transform in the compression algorithm was used. The influence of sampling frequency, length of data frame, type of wavelet function, number of wavelet decomposition stages and quantization level on the compression ratio and compression quality was investigated.

Keywords: lifting wavelet transform, signal compression, power system monitoring

Full paper (2520kB)
p. 85 contents

WITOLD KRIESER

Silesian University of Technology
Gliwice, Polska
e-mail: witkries@sisco.pl

POSITIONING THE SENSOR IN SAMPLING FLOWMETERS

Flow-rate measurements have very important meanings in industry. The sampling flowmeters are devices which can be used for measuring the flow-rate in situations where full-bore flowmeters cannot be used for technical or economical reasons. The main problem in the flow-rate measurement with the help of sampling flowmeters is optimal positioning of the sensor in the pipe. When we use a mathematical model of a sensor and a mathematical model of an object, we can theoretically optimize the position of the sensor in the pipe.

Keywords: flowmeters, mathematical models

Full paper (242kB)
p. 91 contents

JAKUB PIWOWARCZYK, KRZYSZTOF PACHOLSKI

Technical University of Lodz
Faculty of Electrical, Electronic, Computer and Control Engineering
Institute of Circuit Theory, Measurement Science and Material Science
Poland, e-mail: sakla@wp.pl

UTILIZATION OF LEVENBERG-MARQUARDT'S METHOD FOR IDENTIFICATION OF THE ELECTRONIC CURRENT TRANSDUCER WITH A HALL EFFECT SENSOR IN A FEEDBACK LOOP

The utilization of Levenberg-Marquardt's method (LM) for the identification of an unknown model parameters of the electronic current transducer with a Hall effect sensor in the negative feedback loop has been described. The saturation reasons of the electronic block in the transducer model have been also taken into consideration which made it possible to use the model in error analysis of the electronic transducer while deformed signals are being measured in the power electronics and automation.

Keywords: electronic current transducer, identification methods, Levenberg-Marquardt's method

Full paper (2653kB)
p. 105 contents

ADAM ŻUCHOWSKI

Szczecin University of Technology
Poland
e-mail: chlod@ps.pl

ANALOG DOT RECORDING AS AN EXEMPLARY PROBLEM IN THE AREA OF DYNAMIC MEASUREMENTS

Analog recorders as typical measuring instruments disappear from contemporary equipment due to progress of digital measurements and common possibilities of measurement data storage in a computer memory. However, recorders can be improved by application of the idea of modelbased control. It creates new, even surprising possibilities. These incline to deep considerations.

Keywords: dot recording, dynamic measurement

Full paper (5026kB)
p. 117 contents

IGOR P. ZAKHAROV, SERGEY V. VODOTYKA

Kharkov National University Of Radioelectronics
Ukraine
e-mail: newzip@ukr.net

APPLICATION OF MONTE CARLO SIMULATION FOR THE EVALUATION OF MEASUREMENTS UNCERTAINTY

The Monte Carlo procedure for evaluation of uncertainty in measurements is considered. Algorithms of formation correlation and non correlation data files of the input quantity estimated on types A and B are developed.

Keywords: uncertainty in measurement, Monte Carlo simulation, correlation, standard uncertainty

Full paper (597kB)