POLISH ACADEMY OF SCIENCES

Division IV: Engineering Sciences

Committee on Metrology
and Scientific Instrumentation
VOLUME XVII - NUMBER 1/2010 [previous] [next]

CONTENTS

1. A. Zięba - Effective number of observations and unbiased estimators of variance for autocorrelated data - an overview003
2. A. Weckenmann, T. Werner - Holistic qualification in manufacturing metrology by enhanc-ing knowledge exchange among different user groups017
3. P. Arpaia, L. Fiscarelli, G. La Commara - Advanced user interface generation in the software framework for magnetic measurements at CERN027
4. Y.A. Bumai, A.S. Vaskou, V.K. Kononenko - Measurement and analysis of thermal parameters and efficiency of laser heterostructures and light-emitting diodes039
5. A. Weckenmann, J. Bernstein - Optical multi-sensor metrology for extruded profiles047
6. J. Vedral, M. Kříž - Signal processing in partial discharge measurement055
7. F. Corrêa Alegria, F. Martins Travassos - The choice between analogue or digital AC power measurement in a Vodafone base station data logger065
8. H. Madura, M. Kastek, T. Sosnowski, T. Orżanowski - Pyrometric method of temperature measurement with compensation for solar radiation077
9. L. Swędrowski - Current measurements and analysis for induction motor diagnostics087
10. B. Stawarz-Graczyk, D. Dokupil, P. Flisikowski - A method of RTS noise identification in noise signals of semiconductor devices in the time domain095
11. J. Sładek, R. Sitnik, M. Kupiec, P. Błaszczyk - The hybrid coordinate measurement system as a response to industrial requirements109
12. P. Pawlus, R. Reizer - Modeling profiles after vapour blasting119
13. R. Z. Morawski - Nestors of measurement science and technology. Ludwik Finkelstein - the 80th Anniversary
14. R. Z. Morawski - 2009-2010 Activities of International Measurement Confederation IMEKO

ABSTRACTS & FULL PAPERS

003 contents

EFFECTIVE NUMBER OF OBSERVATIONS AND UNBIASED ESTIMATORS OF VARIANCE FOR AUTOCORRELATED DATA - AN OVERVIEW

Andrzej Zięba

AGH University of Science and Technology, Department of Physics and Applied Computer Science, A. Mickiewicza 30, 30-059 Kraków, Poland (zieba@novell.ftj.agh.edu.pl, +48 12 617 3551)

Abstract
When observations are autocorrelated, standard formulae for the estimators of variance, s2, and variance of the mean, s2(x), are no longer adequate. They should be replaced by suitably defined estimators, sa2 and sa2(x), which are unbiased given that the autocorrelation function is known. The formula for sa2 was given by Bayley and Hammersley in 1946, this work provides its simple derivation. The quantity named effective number of observations neff is thoroughly discussed. It replaces the real number of observations n when describing the relationship between the variance and variance of the mean, and can be used to express sa2 and sa2(x) in a simple manner. The dispersion of both estimators depends on another effective number called the effective degrees of freedom veff. Most of the formulae discussed in this paper are scattered throughout the literature and not very well known, this work aims to promote their more widespread use. The presented algorithms represent a natural extension of the GUM formulation of type-A uncertainty for the case of autocorrelated observations.

Keywords: autocorrelated, time series, estimator, unbiased, variance, effective number of observations.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 426kB)
017 contents

HOLISTIC QUALIFICATION IN MANUFACTURING METROLOGY BY ENHANCING KNOWLEDGE EXCHANGE AMONG DIFFERENT USER GROUPS

Albert Weckenmann, Teresa Werner

University Erlangen-Nuremberg, Chair Quality Management and Manufacturing Metrology, Naegelsbachstrasse 25, D -91052 Erlangen, Germany (Albert.Weckenmann@qfm.uni-erlangen.de, Teresa.Werner@qfm.uni-erlangen.de, +49 9131 8526 516)

Abstract
To gather reproducible measurement results, metrologists need a variety of competences. Yet, also other groups of staff in a manufacturing enterprise need competences in metrology in order to assure the appropriate specification of tolerances or sufficient consideration of inspectional requirements in production processes.
Therefore, the strict focus of metrological qualification on staff preparing or performing the actual measurements is insufficient for the efficient assurance of conformity. Additionally, on the one hand a demand-oriented qualification concept is needed to impart required fundamental knowledge on manufacturing metrology according to the specific needs of each user group. On the other hand, appropriate measures of knowledge management have to be applied in order to assure a proper application of the gathered knowledge and enhance mutual understanding for the requirements of other involved user groups.
Thus, as amendment for user-specific measures of formal qualification, a concept has been developed to enable knowledge transfer among different groups and departments in an enterprise. By this holistic approach, the impact of measures of qualification can be increased and high product quality can be achieved as a common aim of all related groups of staff.

Keywords: advanced training, Life Long Learning, knowledge management, holistic qualification.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 356kB)
027 contents

ADVANCED USER INTERFACE GENERATION IN THE SOFTWARE FRAMEWORK FOR MAGNETIC MEASUREMENTS AT CERN

Pasquale Arpaia1,2), Lucio Fiscarelli1,2), Giuseppe La Commara1)

1) University of Sannio, Faculty of Engineering, Piazza Roma, 21-I 82100 Benevento, Italy (arpaia@unisannio.it, g.lacommara@gmail.com)
2) CERN, Department of Technology, Group of Magnets Superconductors Cryostats, CH 1211 Geneva 23, Switzerland (lucio.fiscarelli@cern.ch, +41227671031 )

Abstract
A model-based approach, the Model-View-Interactor Paradigm, for automatic generation of user interfaces in software frameworks for measurement systems is proposed. The Model-View-Interactor Paradigm is focused on the "interaction" typical in a software framework for measurement applications: the final user interacts with the automatic measurement system executing a suitable high-level script previously written by a test engineer. According to the main design goal of frameworks, the proposed approach allows the user interfaces to be separated easily from the application logic for enhancing the flexibility and reusability of the software. As a practical case study, this approach has been applied to the flexible software framework for magnetic measurements at the European Organization for Nuclear research (CERN). In particular, experimental results about the scenario of permeability measurements are reported.

Keywords: software measurement systems, magnetic measurements, automatic test equipment (ATE).

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 390kB)
039 contents

MEASUREMENT AND ANALYSIS OF THERMAL PARAMETERS AND EFFICIENCY OF LASER HETEROSTRUCTURES AND LIGHT-EMITTING DIODES

Yurii A. Bumai1), Aleh S. Vaskou1), Valerii K. Kononenko2)

1) Belarusian National Technical University, Independence Ave., 65, 220013 Minsk, Belarus (bumai@tut.by, o_vascov@mail.ru)
2) Stepanov Institute of Physics NASB, Independence Ave., 70, 220072 Minsk, Belarus (lavik@dragon.bas-net.by, + 375 17 2840 435)

Abstract
A thermal resistance characterization of semiconductor quantum-well heterolasers in the AlGaInAs-AlGaAs system (λst ≈ 0.8 µm), GaSb-based laser diodes (λst ≈ 2 µm), and power GaN light-emitting diodes (visible spectral region) was performed. The characterization consists in investigations of transient electrical processes in the diode sources under heating by direct current. The time dependence of the heating temperature of the active region of a source ΔT(t), calculated from direct bias change, is analyzed using a thermal RTCT equivalent circuit (the Foster and Cauer models), where RT is the thermal resistance and CT is the heat capacity of the source elements and external heat sink. By the developed method, thermal resistances of internal elements of the heterolasers and light-emitting diodes are determined. The dominant contribution of a die attach layer to the internal thermal resistance of both heterolaser sources and light-emitting diodes is observed. Based on the performed thermal characterization, the dependence of the optical power efficiency on current for the laser diodes is determined.

Keywords: heterostructure, light-emitting diode, thermal resistance, efficiency.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 471kB)
047 contents

OPTICAL MULTI-SENSOR METROLOGY FOR EXTRUDED PROFILES

Albert Weckenmann, Johannes Bernstein

University Erlangen-Nuremberg, Chair Quality Management and Manufacturing Metrology, Naegelsbachstr. 25, 91052 Erlangen, Germany, (Albert.Weckenmann@qfm.uni-erlangen.de, bernstein@qfm.uni-erlangen.de, +49 9131 852 6545)

Abstract
Nowadays the process-control of concave extruded profiles is a measuring task with rising requirements. A novel optical bi-sensorial measurement system - consisting of a shadow- and a light-section-system - as well as suitable methods of analysis for in-line inspection are presented. The proposals help to ensure the product quality on a higher level than before. The combination of dimensional accuracy and data-density leads to excellent results. Extruded profiles are semi-finished products (from steel, brass, aluminum, synthetics...) which are appointed for wide applications in technical products. For monitoring and controlling the parts in-line adequately, today often the shading technology is used. It detects - neglecting the profiles coat in measurement range - with high precision the dimension of the objects shadow orthographically to the axis of illumination. As a matter of fact, concave and local areas cannot be recorded. Alternatively, light-section-systems can measure concave zones and undercut zones but do not comply with the required accuracy. The combination of accuracy and data-density qualifies the mentioned multi-sensor metrology for realizing a maximum of efficiency in process control what ensures product quality and less defective goods. The optical multi-sensor measurement system has to be calibrated and aligned to detect the same surface zone despite of high refresh rates and optical resolutions. The metered characteristics will be coordinate transformed to extrinsic world-coordinates for evaluating form deviations of complex parts. An appropriate user-interface enables to re-calculate measurement objects in-line and evaluate the conformity of the part consequently. Finally the real length information assists to influence the process control. After a successful test in the laboratory the results will be proved in production to the target: measurement uncertainty of better than 0.1 mm at every profile.

Keywords: multi-sensor-measurement, optical measurement, laser scanning.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 580kB)
055 contents

SIGNAL PROCESSING IN PARTIAL DISCHARGE MEASUREMENT

Josef Vedral, Martin Kříž

Czech Technical University, Faculty of electrical Engineering, Department of Measurement, Technická 2, 166 27 Praha 6, Czech Republic(vedral@fel.cvut.cz, +420 22 435 2182, martikriz@gmail.com)

Abstract
The paper presents traditional analogue and digital techniques in partial discharge measurement. The discharge current pulses are measured from high voltage machines like power plant generators and transformers. The presented modern digital techniques are suitable for all measurements where impulse energy will be calculated.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 827kB)
065 contents

THE CHOICE BETWEEN ANALOG OR DIGITAL AC POWER MEASUREMENT IN A VODAFONE BASE STATION DATA LOGGER

Francisco Corrêa Alegria1), Francisco Martins Travassos2)

1) Instituto de Telecomunicações e Instituto Superior Técnico, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal (falegria@lx.it.pt, +351 218 418 376)
2) Nokia Siemens Networks Portugal, Rua Irmãos Siemens, 1, 2720 - 093 Amadora, Portugal (ciscotravas@gmail.com)

Abstract
A data logger has been built to record, for a month, the power consumption of various equipment and the temperature at different points inside and outside of a radio communication base station operated by Vodafone Portugal. Here we show how the concerns with measurement uncertainty led us to choose an analog system over a digital one for AC power measurement.

Keywords: AC power measurement, automatic system, data logging.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 409kB)
077 contents

PYROMETRIC METHOD OF TEMPERATURE MEASUREMENT WITH COMPENSATION FOR SOLAR RADIATION

Henryk Madura, Mariusz Kastek, Tomasz Sosnowski, Tomasz Orżanowski

Military University of Technology, Institute of Optoelectronics, S. Kaliskiego 2, 00-908 Warsaw, Poland (hmadura@wat.edu.pl, +48 22 6839 383, mkastek@wat.edu.pl, tsosnowski@wat.edu.pl, torzanowski@wat.edu.pl )

Abstract
Outdoor remote temperature measurements in the infrared range can be very inaccurate because of the influence of solar radiation reflected from a measured object. In case of strong directional reflection towards a measuring device, the error rate can easily reach hundreds per cent as the reflected signal adds to the thermal emission of an object. As a result, the measured temperature is much higher than the real one. Error rate depends mainly on the emissivity of an object and intensity of solar radiation. The position of the measuring device with reference to an object and the Sun is also important. The method of compensation of such undesirable influence of solar radiation will be presented. It is based on simultaneous measurements in two different spectral bands, short-wavelength and long-wavelength ones. The temperature of an object is derived from long-wavelength data only, whereas the short-wavelength band, the corrective one, is used to estimate the solar radiation level. Both bands were selected to achieve proportional changes of the output signal due to solar radiation. Knowing the relation between emissivity and solar radiation levels in both spectral bands, it is possible to reduce the measurement error several times.

Keywords: intensity of solar radiation, emissivity, pyrometry, radiometric temperature measurements.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 552kB)
087 contents

CURRENT MEASUREMENTS AND ANALYSIS FOR INDUCTION MOTOR DIAGNOSTICS

Leon Swędrowski

Gdansk University of Technology, Faculty of Electrical and Control Engineering, G. Narutowicza 11/12, 80-952 Gdańsk, Poland (l.swedrowski@ely.pg.gda.pl, +48 59 347 1258)

Abstract
Additional motor vibrations are the result of a faulty bearing. They are reflected in the harmonic content of stator currents. The object of the investigation presented in the paper are measurements related to diagnostics of induction motors, especially damages caused to bearings. Due to the fact that the amplitude of the network voltage basic harmonic in the current spectrum is high in comparison with components responsible for damages of bearings, preliminary elimination of this component from the analog current signal has been proposed.
The problem with interpretation of diagnostic measurements in present systems is the difference between measurement results of characteristic frequencies and theoretical calculations.
In the proposed measurement system this problem was solved in such a way that the value of the angular speed and of the supply frequency is calculated on the basis of appropriate components in the very same current spectrum that is further used in the search for diagnostic components.
The paper presents also the measuring system and provides results of the investigations carried out on a motor encumbered with a specially prepared defect.

Keywords: induction motors, current measurement, diagnostics, roller bearing, spectral analysis.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 347kB)
095 contents

A METHOD OF RTS NOISE IDENTIFICATION IN NOISE SIGNALS OF SEMICONDUCTOR DEVICES IN THE TIME DOMAIN

Barbara Stawarz-Graczyk, Dariusz Dokupil, Paweł Flisikowski

Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, G. Narutowicza 11, 80-233 Gdańsk, Poland (bstawarz@eti.pg.gda.pl, +48 58 347 1484, ddokupil@gmail.com, flisgd@poczta.fm)

Abstract
In the paper a new method of Random Telegraph Signal (RTS) noise identification is presented. The method is based on a standardized histogram of instantaneous noise values and processing by Gram-Charlier series. To find a device generating RTS noise by the presented method one should count the number of significant coefficients of the Gram-Charlier series. This would allow to recognize the type of noise. There is always one (first) significant coefficient (c0) representing Gaussian noise. If additional coefficients cr (where r > 0) appear it means that RTS noise (two-level as well as multiple-level) is detected. The coefficient representing the Gaussian component always has the highest value of all. The application of this method will be presented on the example of four devices, each with different noise (pure Gaussian noise signal, noise signal with two-level RTS noise, noise signal with three-level RTS noise and noise signal with not precisely visible occurrence of RTS noise).

Keywords: RTS noise, Gram-Charlier series, semiconductor devices, optocouplers.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 1863kB)
109 contents

THE HYBRID COORDINATE MEASUREMENT SYSTEM AS A RESPONSE TO INDUSTRIAL REQUIREMENTS

Jerzy Sładek1), Robert Sitnik2), Magdalena Kupiec3), Paweł Błaszczyk2)

1) Cracow University of Technology, Laboratory of Coordinate Metrology, Jana Pawła II 37, 31-864 Cracow, Poland (sladek@mech.pk.edu.pl)
2) Warsaw University of Technology, Institute of Micromechanics and Photonics, Św. A. Boboli 8, 02-505 Warsaw, Poland (r.sitnik@mchtr.pw.edu.pl, p.blaszczyk@mchtr.pw.edu.pl)
3) State Higher Vocational School, Institute of Engineering, Staszica 1, 33-300 Nowy Sącz, Poland (magdalena.kupiec@gmail.com, +48 506 999 479)

Abstract
The tendencies of modern industry are to increase the quality of manufactured products, simultaneously decreasing production time and cost. The hybrid system combines advantages of the high accuracy of contact CMM and the high measurement speed of non-contact structured light optical techniques. The article describes elements of a developed system together with the steps of the measurement process of the hybrid system, with emphasis on segmentation algorithms. Additionally, accuracy determination of such a system realized with the help of a specially designed ball-plate measurement standard is presented.

Keywords: optical scanner, CMM, accuracy, segmentation, calibration.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 1043kB)
119 contents

MODELING PROFILES AFTER VAPOUR BLASTING

Paweł Pawlus1), Rafał Reizer2)

1) Rzeszow University of Technology, Department of Manufacturing Processes and Production Organization, W. Pola 2, 35-959 Rzeszów, Poland (ppawlus@prz.rzeszow.pl, + 48 17 865 1183)
2) University of Rzeszow, Institute of Technology, Rejtana 16A, 35-959 Rzeszów, Poland (rreizer@univ.rzeszow.pl)

Abstract
The irregularity profiles of steel samples after vapour blasting were measured. A correlation analysis of profile parameters was then carried out. As the result, the following parameters were selected: Pq, Pt, PΔq, Pp/Pt and Pku. Surface profiles after vapour blasting were modeled. The modeled surfaces were correctly matched to measured surfaces in 78% of all analyzed cases. The vapour blasting experiment was then carried out using an orthogonal selective research plan. The distance between the nozzle and sample d and the pressure of feed system p were input parameters; selected surface texture coefficients were output parameters. As the result of the experiment, regression equations connecting vapour blasting process parameters p and d with selected profile parameters were obtained. Finally, 2D profiles of steel samples were forecasted for various values of vapour blasting parameters. Proper matching accuracy of modeled to measured profiles was assured in 75% of analyzed cases.

Keywords: surface topography, simulation, forecasting.

© 2010 Polish Academy of Sciences. All rights reserved

Full paper (PDF, 368kB)