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PAPER SECTION 3

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VOLUME 3,  2003

  Measurement of Physical Quantities

 

 

 1-4 Zakrzewski J.:
Error Propagation in Interface Electronics for Passive Sensors

Abstract: Contemporary interface electronics for passive sensors may be divided into three groups according to the output variable: frequency output, voltage output and pulse duration modulated output. The paper presents the basic principles of error propagation for only two groups. The error propagation depends mostly on the sensor properties (“m” coefficient) and on the structure of the interface electronics (nondifferential or differential one). For sensors with low “m” values the similarity of error propagation for both investigated groups has been found in spite of the great differences in their design. Specific properties of quasi-differential strictures - like bridges – are presented too.

5-8

Malarić K., Bartolić J., Modlic B.:
Instrumentation for Electromagnetic Compatibility Measurements

Abstract: Measurements in the electromagnetic compatibility are important because today every aspect of life and the industry depends on how much interference there is, whether some device will operate accordingly to the desire, and with what efficiency. The instrumentation for such measurements is evolving all the time, especially lately, since the number of devices and electronic disruptions is growing. In last twenty years extensive research has been performed regarding the improvement of the instrumentation for the electromagnetic (emc) measurements. TEM and GTEM cell have been developed, with improved characteristics.

 

 9-12
Frollo I., Andris P., Strolka I.:
Measuring Method and Magnetic Field Homogeneity Optimisation for Magnets Used in NMR-Imaging

Abstract: Description of a simple and fast method for computation of feeding currents of shim coils for stationary magnetic field used in NMR imaging is the scope of this paper. The method needs to perform a magnetic field measurement in selected points of an assigned volume twice: when shim coils are switched off and afterward the measurement of magnetic field changes caused by switching on the feeding current of particular shim coil in each of selected points. A set of linear equations definition, determination of a target function and optimisation computations are procedures that provide optimal values of currents for shim coils. The proposed method because of its simplicity and speed of computation is convenient for basic adjustment of the magnetic field homogeneity by first magnet installation. It is also suitable for periodic testing and magnet inhomogeneities correction for MRI magnets especially in the case when the magnetic properties of the magnet surroundings are changed.

13-16
Andris P., Weis J., Frollo I., Ericson A.:
RF Coil Magnetic Field Measurement by NMR Method

Abstract: A spectroscopic imaging technique with high spatial resolution was used for the measurement of the static magnetic field homogeneity of RF coils. Measured magnetic fields of optimised and not optimised saddle-shaped coils were compared with the theoretical calculations. Results are in good qualitative agreement between calculated and measured magnetic field distributions. Quantitative disagreements however appeared in some experiments. We suppose that the method is suitable for magnetic field measurement of RF coils operating at frequencies where RF magnetic field may be replaced by the static magnetic field.

 17-20
Starčuk Z., Starčuk Z. jr., Horký J.:
"Baseline" Problems in Short Echo-time Single Voxel 1H MR Spectroscopy of the Brain

Abstract: Accurate and reliable quantification of low molecular weight metabolites in short echo-time proton MR spectra of the brain is usually considerably complicated by an uncharacterized broad baseline extending over the whole frequency range of the metabolite signals of interest. Several sequences providing pure MR spectra of cerebral metabolites were designed, computer analyzed and experimentally tested. In these sequences, precautions have been made to avoid baseline contributions due to experimental imperfections, and signals of low molecular  weight metabolites were distinguished from those of macromolecules (lipids), which are substantial contributors to the broad baseline, by utilizing the differences between their T1 relaxation times. 

 21-24
Grman J.:
Application of Wavelet Transformation in Eddy Current Testing

Abstract:  Fast localization of indications of defects and structure elements in the defectoscopy of steam generator tubes is the field where application of wavelet transformation is very perspective. Our primary task is to find positions of potential indications within signal and secondary task is to calculate optimal boundaries of indications with respect to their future use in process of classification. The contribution concentrates on the choice of suitable wavelet function and parameters of localization algorithm. Basic result of this algorithm is vector of positions of indications within signal. Use of multiresolution wavelet analysis implies a possibility to calculate optimal boundaries of found indications. Selected algorithm and his parameters were compared using real records of steam generator tubes and artificial defects and imitations of construction elements as well. 

 25-28
Grman J., Ravas R., Syrová L.:
Application of Neural Networks in Multifrequency Eddy-Current Testing

Abstract: The nondestructive defectoscopy of steam generator tubes of nuclear power plants by multifrequency eddy current method is the field, in which the use of classifiers, based on neural network is very perspective.One of the fields is classification of indications into classes, that are characterized by the signal shape, eventually by the signatures relating to the signal shape. The contribution concentrates on the choice of suitable neural network structures and of the suitable representation of indications.

 29-32

Bartl J., Fíra R., Hain M.:
Inspection of Surface by the Moiré Method

Abstract: A moirè method is one of the optical methods which are suitable for measurement of length, angle of rotation and also contactless surface shape deviation evaluation. The article is concerned on the possibilities of application this method by the evaluation of plane surface deviation of the semiconductor wafers. 

 33-36

Plesch G., Van Driessche I., Cigáň A., Maňka J., Hoste S., Kliment J.:
Influence of Synthetic Processing on the Magnetic Properties of Superconducting YBa2Cu3O7/Ag Composites
Abstract:  The AC magnetisation measurements and scanning electron microscopy show that the percolation threshold of silver metal in the YBa2Cu3O7- /Ag composites is crucially dependent on the method of the preparation. In the case when the sintering is performed under the conditions of the eutectic melt formation, this threshold is shifted to lower values. At 20 wt % Ag addition, the silver layer precipitated on grain boundaries fully interrupts the intergranular superconducting links. 

 37-40

Cigáň A., Andrzejewski B., Plesch G., Gritzner G., Maňka J., Zrubec V.:
Magnetic flux penetration into (Tl0.6Pb0.5)(Ba0.1Sr0.9)2 Ca2Cu3Ox and (Tl0.8Bi0.3)(Ba0.1Sr 0.9)2 Ca2Cu3Oy bulk pellet samples
Abstract:  Magnetic field penetration into (TI0.6Pb0.5)(Ba0.1Sr 0.9)2Ca2Cu3Ox and (Tl0.8Bi0.3) (Ba0.1Sr0.9)2Ca2Cu3Oy  bulk pellet samples was investigated by two methods: (i) by the volume  magnetization and (ii) by the local scanning Hall method. Pb-doping resulted in stronger inter-grain links and improved the intra-grain critical current densities. Bi-doping instead of Pb-doping increased the critical temperature from 113 K to 116 K. Considering that bulk pinning of the doped Tl-1223 samples is low and that the magnetic field penetration is predominantly determined by geometrical barrier effects, the characteristic magnetic penetration fields obtained by the two methods are inexcellent agreement.

 41-44

Koňakovský A., Cigáň A., Maňka J., Buchta ©.:
Cryogenic Probe and Apparatus for Contactless Measurement of Transition Characteristics of HTc Superconductors
Abstract:  Cryogenic probe and automatic apparatus for study of transition properties of HTc superconductors was developed using the inductive measurement method. The superconducting sample is sandwiched between the primary and secondary coils. Transition of the sample into the superconducting state results to significant changes of mutual inductance and that way to the changes of the output voltage of secondary coil. Comparison of the results of the four point transport and the contactless inductive method of the measurement of transition curves of the YBa2Cu3O7-d -(Sc) samples is presented. It is shown, that these two methods can lead to consistent or complementary results in Tc measurements. It depends on such characteristics of HTc compounds as are composition, content of superconducting phase or homogenity. 

45-48

Hanic F., Cigáň A., Buchta Š., Maňka J., Zrubec V.:
A Possible Using of Superconducting Measurements to Better Understanding of Catalytic Properties of YBa2Cu3Ox

Abstract: The high temperature YBa2Cu3Ox (Y-123) superconductor represents a new class of oxidation catalysts. It allows to achieve desired activity, selectivity and stability of the catalyst due to presence of active copper cites in the - Cu-O-chains along the [010] direction. They are closely related to the x –value adjustable by quenching the sintered Y-123 sample from the properly selected temperature level at suitable pO2 parameter. The x-value can be estimated from the critical temperature Tc or crystallographic measurements. Stability and intergrain bonding can be inferred from magnetization measurements in superconductive state at low magnetizing field. Some measure of openness or closeness of pores can be estimated from magnetic susceptibility measurements. Conditions for the regeneration of the catalyst can be easily carried out due to high mobility of oxygen along the copper chains at proper temperature and pO2. The stability of structural skeleton and formation of open pores in the sample can be easily regulated by the sintering temperature. It was realized in the range 910 °C up to 950 °C in this work. 

49-52 Hanic F., Cigáň A., Buchta ©., Maňka J., Zrubec V.:
Identification of Single-domain Structures in the System YBa2Cu3O7-?-Ag by Magnetization Measurements

Abstract: The magnetization methods were used in study of effect of Ag doping on the structural and superconducting parameters in two series of melted and highly textured samples of the system (YBa2Cu3 O 7-d)1-x(Ag2O)x. The x concentration level of the first series ranged from 0 to 10 wt % and the second one from 0 to 3.6 wt % Ag2O. By means of the SQUID magnetization measurements the optimum Ag2O doping level ranged from 1.6 to 2.8 wt %. These methods led to optimization of conditions in preparation of single-domain samples. From the secondary precipitated CuO phase and from the appearance of Ag component the solubility limit of Ag in solid solution YBa2Cu3-yAgyO7-y/2-d was found.

53-56 Štrbík V., Chromik Š., Beňačka Š., Plecenik A., Gaži Š.:
Superconducting Tl- and Hg-based Cuprate Thin Films

Abstract: We have prepared and studied both Tl- and Hg-based high critical temperature superconducting (HTS) thin films. The standard two-step fabrication procedure was used. Ba-Ca-Cu-(O,F) precursor film was prepared from fluorides BaF2, CaF2 and metallic Cu at room temperature. After ex-situ thallination or mercuration of the precursor film at high temperature 750 - 860 °C the superconducting Tl- and Hg-based cuprate thin films were obtained. The zero resistivity critical temperature above 100 K was reached for both types of HTS. The estimated transport critical current densities were 104 A/cm2 at 77 K for Tl- and 104 A/cm2  at 100 K for Hg-based cuprate thin films. The stability of the films properties uring more than 1 year will be presented.

57-60 Šimáček I., Maňka J., Krutý F.:
Quantification of Low Concentration of Ferromagnetic Particles by SQUID Magnetometric Method

Abstract: The results of direct measurements of the remanent magnetic induction (RMI) of some powdered ferromagnetic materials (PFM) with the help of the SQUID magnetometric system (SMS) are given. The study was performed to evaluate the magnetic characteristics of the powdered PFM and the dependencies of RMI on their planar concentration. Based on measurements of the groups of samples with PFM, the minimum measurable planar concentrations for selected materials were determined. Magnetic measurements of this kind may be useful for quantifying the lung dust retention in clinical practice.

61-64

Zrubec V.:
Noise Properties of the SQUID-systems for Measurement of AC Magnetization Characteristics of HTc Superconductors by the Compensation Method
Abstract: This contribution deals with analysis of the influence of the topical noise sources on the resulting sensitivity of the measuring system in magnetically unshielded environment. The geomagnetic noise in the measuring ambient, the noise component of the magnetisation field and the intrinsic noise of the superconducting quantum gradiometer (SQG) are considered. The results of the theoretical analysis are applied in the system with the magnetisation coils and the distance of the superconductor sample from the xs = 10,7 cm. In typical conditions of magnetically unshielded Faraday chambers placed at the border of the town area, it is possible to achieve the spectral sensitivity of the order of (10-9 ¸ 10-10) Am2 Hz-1/2. 

65-68 Boháková F., Maňka J., Cigáň A.:
Measurement of Multiple Magnetization Characteristics of High Tc Superconductors

Abstract:  In this paper we present tools for measurement of multiple magnetization characteristics using the compensation techniques and the 2 -order  SQUID gradiometric apparatus. The examples of the multiple measurements of AC and virgin DC magnetization M vs. applied magnetic field Ha dependencies of HTc superconductors are shown. Usefulness of the multiple characteristics is discussed.

 

 69-72

Jermak J., Rucki M.:
The Advantageous Statical Metrological Properties of the Pneumatic Sensor with Two Skewed Nozzles
Abstract: In the article, the concept and the main statical metrological properties of the pneumatic sensor with two skewed nozzles are presented. The sensor was designed to improve metrological characteristics of the pneumatic sensors by means avoiding the axis-symmetrical outflow. Investigations have proved that generally static characteristic of the sensor is advantageous comparing to the simple pneumatic gauges, i.e. it has higher sensitivity for the same measuring range. Fluctuations of the outflowing air in the measuring slot are smoother, so they don't limit the increase of the measuring range. There are also more possibilities of forming the characteristics of the sensor depending on application requirements. 

 73-76

Bittera M., Harťanský R., Kováč K.:
One Way to Provision of HF E-field Sensor Isotropy
Abstract: The aim of the paper is to ensure the isotropy of sensor of electric component of electromagnetic field. Sensor consists of three independent dipoles. The mathematical model of radiation pattern of each dipole is presented, as well as the methodology of final sensor characteristic and final pattern estimation. The results are verified by measurements on three resistive dipoles and compared to each other.

 77-80

Jabloński J., Pawlus P.:
Theoretical Considerations of Surfaces Having Stratified Functional Properties
Abstract: The paper is devoted to the analysis of stratified functional surfaces. The profiles after two processes were computer generated using the special procedure. The parameters of the resulting profile were studied as the function of input parameters. 

 81-84

Nieciag H., Chuchro Z.:
Taking Advantage of Integrated Software Environment in New IOS Three-coordinate Measuring Machines Software System Designing
Abstract: The paper presens the concept of new software system of three-coordinate measuring machines produced by IOS based on integrated software environment techniques. System manages a relational database, organised for collection of all necessary data and information in measuring process. The basic architecture and its implementation are discussed. New perspectives for cooperation of the system with another program environments are also shown. 

 85-88

Pawlus P., Jabloński J.:
Cumulative Curves Characterising Load Carrying Capabilities and Wear Properties of Surfaces
Abstract: The possibilities of generating various cumulative curves were studied. The mutual positions of these curves were analysed basing on computer-generated profiles of various shapes and real profiles of cylinders. 

 89-92

Durakbasa M.N., Afjehi-Sadat A., Nomak A.:
Dimensional and Geometrical Measurements and Interpretation of Measuring Results on the Basis of the Skin-model
Abstract: Geometrical Product Specification and Verification (GPS) are a means to transform function dependent demands as defined by the customer into produced work pieces. The newly developed so-called Skin-Model allows the complete implementation of Geometrical Product Specification and Verification into Co-ordinate Metrology and vice versa. Selected series of work pieces from industrial manufacturers are measured in a precision measuring laboratory and based on the measurement results gained it is possible to carry out extensive evaluations by using statistical methods e.g. correlation analysis. This allows to get information about interrelationships between different geometrical deviations and on this basis it is possible to influence manufacturing conditions for decreasing production costs and increasing product quality. 

 93-96

Michalecki G.:
Automatic Calibration of Gauge Blocks Measured by Optical Interferometry

Abstract: Construction and principle of operation of automatic interferometer for measurements of gauge blocks were described. The possibilities of  the system based on phase shifting method and the software elaborated in Length and Angle Division of Central Office of Measures and Optical Engineering Division Œ Department of Precision Mechanics of Warsaw University of Technology were presented. 

 97-101

Mokroš J., Hain M.:
Calibration of Large Square Standards
Abstract: In this paper the principle and device NME 90 0 for large square standards calibration is described. The self-calibration methods of measurement are used. They allow very low uncertainty of the square calibration with mathematical elimination of measuring column straightness deviations. The process of measurement is full automated and controlled by PC, which collects and evaluates measured data. The uncertainties of the square measurement are also discussed in the paper.  

 103-106

Ravas R.:
Automation of Evaluation of Measurement in Defectoskopy of Power Steam Generator
Abstract: Automated assessment of steam generator tubes by eddy current method is associated with classification of indications into classes which correspond to the responses of the measured signal of steam geneator construction elements as are supports, defects of tube material and artificial defects of calibration tube. Contribution concentrates on the description of automated assessment of defectoscopic measurement. Suitable choice of methods of detection and location of indications, classification of indications into classes and quantification of defect parameters are very important. 

 107-110

Syrová L.:
Application of Visualization Methods
Abstract:  The contribution treats the principles of optical visualization methods applied to the flow characteristics and velocity profiles measurement and to the evaluation of properties of optically transparent materials , especially transparent polymeric foils. 

 111-114

Frollo I., Andris P., Plačková A.:
Measurement and Imaging of Long Samples Using Nuclear Magnetic Resonance
Abstract: NMR - measurement and imaging of a spin density distribution of long samples needs a special arrangement of the radio-frequency and gradient coils placed on a long cylinder. The paper deals with a method of calculation and optimisation of four-wire radio-frequency coil geometry where the homogeneity in the central region as a transverse cross-section of a measured cylinder is evaluated.The 3D plot and contour plot of the real part of generated field is presented.

 115-118

Andris P.:

Matching and Tuning RF Coils for NMR Tomograph

Abstract: The most used matching circuit for RF coils of NMR tomographs is analysed from the point of view of tuning. Elements of the circuit are calculated in generic form so that the resulting formulas could be used also on high frequencies where parasitic influences may not be neglected. The output impedance of the circuit is calculated and analysed aiming at phenomena occurring during tuning the circuit.

 119-122

Zloto T., Biernacki Z., Kurkowski M.:
Measurements of Selected Parameters of a Hydraulic Pump by Means of a Computer-Based Measuring System
Abstract: The basic characteristic parameters of the pump operation are presented. The parameters are monitored by a computer-based measuring system at a hydraulic stand. The structure of the measuring system and the construction of the measuring converters applied in the system are described.

 123-126

Zloto T.:
Testing the Heating of the Basic Components of an Axial Multipiston Pump
Abstract: In the paper a hydraulic measuring stand for measuring the increases in the temperature of the basic kinematic pairs of a pump is presented. Also, an optoelectronic  sensor for measuring the temperature of the cylinder block is described. The dependence between the increases in the temperature of the basic kinematic pairs and the pressure and temperature of oil at the pump input, by the nominal angular velocity and maximal inclination of the swash plate is discussed. 

 127-130

Biernacki Z., Kurkowski M., Zloto T.:
Correlation Flow-meter with a Thermoanemometric Sensor
Abstract: The paper describes the functioning of the measuring system of a wave thermoanemometer. The effect of the application of a thermal wave induced by forcing quasirandom signals (PRBS) is also discussed. Correlation analysis of signals generated in the receiving wires of  the thermoanemometric sensor is presented. 

 131-134

Biernacki Z., Kurkowski M., Zloto T., Ptak P.:
Analysis of Exploatation and Metrological Properties of a Wave Thermoanemometer System
Abstract: In the paper the functioning of a wave thermoanemometer with a thermoresistive sensor is presented. Three constructional variants of the sensor are described and a computer-aided system of wave thermoanemometer (WTS) is presented. Besides, exploitation properties and metrological characteristics of WTS designed and constructed by the authors are discussed. The relevant mathematical formulae are also presented.

 135-138

Bogdan M., Fita S.:
The Measuring Post of Acoustic Sensors
Abstract: The character of the post described in the paper and used for research on acoustic sensors properties is universal. Measurement of the pressure and air temperature allows calculating the characterisation of the sensor in different conditions. Somebody can wonder if the calculation of Fourier transformation by means of 24-bits DSP works in a situation when, for example, Matlab system is attainable. It seems that the use of universal EVM to convert signals with DSP together with CODEC‘s 20dB amplifier is well founded. Moreover, communication possibilities of the system, such as application of Excel programme to visualisation and data storage, are not devoid of significance. 

 139-142

Mirkowski J., Tutak W.:
The Research of the Random Component of Air Flow Velocity in the Cylinder of the Internal Combustion Engine
Abstract: The paper presents a possibility application of the hot wire anemometer in the investigation of  the random component of velocity air flow in the cylinder IC engine. Digital signal processing allows to evaluate, parameters of the turbulent air flow in the engine cylinder. The algorithm designed for the processing of signal acquired during tests. An important consideration is the influence of static pressure at the CTA signal. The authors took into consideration this factor. The studying flow of air in the internal combustion engines cylinder is necessary. It is one of the ways to improve the parameters of the IC engine. This task is difficult to perform due to the large span of pressures and temperatures. In the chamber of the IC engine the flow field is rapidly changing in a short space of time. One of the passable measurement methods is the constant temperature anemometer.  

 143-145

Mirkowski J., Tutak W.:
Thermal Marker Flowmeter with a Closed Feedback Loop
Abstract: In marker instruments, substances are used which are additionally introduced into the fluid, or the values of physical quantities characterizing the fluid state are locally changed. By investigating the motion of so produced marker, the kinematic parameters of fluid flow can be determined. In practice, thermal markers with moderate parameters are preferably used, due to their noninvasive character. 

 147-150

Adamczak S., Janecki D.:
Problems Concerning the Measurement of Form Profiles of Non-closed Cylindrical Surfaces of Machine Parts
Abstract: The measurement methods applied so far have concerned full (closed) profiles. However, in a number of cases the contact surfaces are not full and their profiles determined in appropriate cross-sections are non-closed. Specialised instruments are used for such measurements. Of particular interest are those constructed mainly for the needs of the bearing industry and used to measure the quality of rolling surfaces of rings. In such cases, a correct measurement requires selecting an appropriate reference circle, in relation to which the deviation of the analysed nonclosed profile will be determined. The paper deals with a theoretical analysis of  the applied reference circles, on the basis of which it was found that the deviation determined for particular reference circles can differ considerably. The work discusses also the theoretical determination of a reference circle, which will lead to the computerisation of measurements of non-closed profiles. 

 151-154

Łukianowicz C., Karpiński T.:
Optical System for Measurement of Surface Form and Roughness
Abstract: An optical system designed for measurement of surface form and roughness is the subject of this paper. The system‘s operation is based on the light scattering from surface irregularities. This system can be used for controlling the rough surfaces of objects under static conditions and while their movement. Measurement of form and surface waviness requires steady-rate displacement of the measuring setup with respect to the object. The principle of the system‘s operation and experimental results obtained from various machined rough surfaces are presented. 

 155-158

Syrová L., Ravas R., Grman J.:
Use of Statistical Approach for Defectoscopy of Visualized Transparent Polymeric Foils
Abstract: The contribution treats the topic of acquiring information on the properties of optically transparent materials by the Schlieren optical visualization method applied under laboratory conditions, and on processing the experimentally gained information. Experimental results obtained on different types of polymeric foil serve as an evidence of applicability of this method in the defectoscopy of transparent polymeric foils using statistical characteristics.  

 159-162

Kiryanov V.P., Nikitin V.G., Verkhogliad A.G.:
Development and research of the scanning method for testing of difraction optical elements
Abstract: The results of scanning method research for testing of diffraction optical elements are shown in this paper. The diffraction efficiency of exemplary diffraction optical element (Fresnel lens) was measured by suggested scanning method and directly (integral) method. Measured data are compared and analyzed. Results of having non-spherical wavefront transformation diffraction optical element measurement are presented and discussed. Conclusions concerning the parameters of the fulfilled phase profile for these diffractive optical elements are tested.

 163-167

Ondriš L., Buzasi J., Keppert M., Krušinský D., Rusina V.:
Dynamic Properties Measurement of the Hydrolevelling System Holmes
Abstract: The hydrolevelling system HOLMES (Hydrostatic Optoelectronic Levelling MEasuring System) is used for the height differences of the Nuclotron accelerator magnets monitoring since 1998 year. In the paper are given the system operation principles, sensor description, measured data evaluation, results presentation and filing. Included are also results of the dynamic properties of the system measurements. 

 169-172

Blaška J., Sedláček M.:
Use of the Integral Transforms for Estimation of Instantaneous Frequency
Abstract: Estimation of the instantaneous signal frequency is at present an important task in the measurement [1]. Choice of the suitable method depends on the type of the measured signal and on the computing capacity of the equipment used. Power-line frequency can serve as an important example. Its deviations from nominal value indicate the imbalance between the generation and the consumption of energy in the net. It can even indicate serious malfunction in a part of the power distribution net. Measurement of instantaneous power-line frequency fiis important also in instrumentation. Changing the length of the first integration tact according to instantaneous power-line period time allows to achieve very high value of the SMRR (series-mode interference rejection ratio) of integrating digital voltmeters. High value of SMRR at the frequency of the power-line voltage and its multiples is one of the conditions for the highest accuracy measurement of the DC voltage with additive AC disturbance. In both the above-mentioned applications, measurement of the instantaneous frequency should be done in short time (preferably as real time measurement). It is therefore very important to implement suitable methods at some of the digital signal processors. Scope of this contribution is oriented mainly to measurement of the power-line instantaneous frequency. Therefore our experiments use signals with frequencies around 50 Hz.

 173-176

Tarata D., Ghita S., Tarata M.:
Stereological Characterization of Pre~and Sintering Phases in PIM Made W-Cu-Ni Electrical Contacts
Abstract: The work deals with the characterization of presintering and sintering phases in powder injection molding (PIM) made W-Cu-Ni electrical contacts. Usually, such electrical contacts are made by pressing. The major drawback of this process is that its applicability is limited to simple shapes. Through powder injection molding the design restrictions are eliminated and the mechanical and electrical properties of the components thus obtained are closed to the pressing technology. The analysis method described in the paper allows collecting data to objectively describe the granulometric repartition of the components in pseudo alloys, and indirectly, their properties. 

 177-180

Celis K., Van Driessche I., Mouton R., Vanhoyland G., Hoste S.:
Kinetics of Consecutive Reactions in the Solid State: Thermal Decomposition of Oxalates
Abstract: The thermal and kinetic aspects of solid state decomposition reactions can be complex and posses a large number of parameters to investigate. The determination of the activation energies for the several intermediates in the thermal decomposition is particularly sensitive to the overlap in thermal decomposition traces. To overcome this problem we have undertaken the detailed kinetic analysis of the well-known thermal decomposition of calcium and strontium oxalates and mixtures of both. Indeed, their small difference in decomposition temperatures, from oxalate to carbonate, allowed us to simulate overlapping TGA signals and to use these data to test the validity of the experimental conditions and mathematical methods used to derive calculated kinetic values. 

 181-181

Celis K., Van Driessche, Mouton R., Hoste S.:
Thermomicroscopy as a Tool to Study the Kinetics of Consecutive Reactions in the Solid State
Abstract: In general, the most reliable theoretical explanations of observed kinetic behavior are based on data obtained from different , but complementary, investigative techniques. The necessity of complementing rate studies conducted by conventional thermal analysis (TA) techniques, e.g. TGA and DTA/DSC, with other types of experimental measurements and observations is emphasized with particular stress on the value of microscopic observations. Solid state chemistry possesses the important advantage that it permits reactions to be visually inspected by microscopy. This approach is sometimes, but not invariably, exploited and it must be commended as the most effective and efficient route towards the elucidation of many aspects of the chemistry of solids. 

 183-186

 

Stein G. J.:
Some Recent Developments in Acceleration Sensors
Abstract: The contribution deals with recent development in acceleration sensors, specifically on MEMS sensors and their use. The various noise sources presented are described. Also a short description of so-called Transducer Electronic data Sheet (TEDS) concepts according to emerging standard IEEE P1451 is included.  

 187-190

Dědek L., Dědková J.:
Numerical Evaluation of Signal in Resistive Plate Chamber

Abstract: Equations for the numerical evaluation of output signals from the resistive plate chamber are presented in the paper. The field of moving charges is described by means of scalar transient electric potential. The displacement and conductive currents are induced in the slightly conductive layer covering pick-up electrodes of an arbitrary shape. These electrodes are connected to currentcontrolled operational amplifiers and so their potential can be set to zero. The potential equations are discretized by the Finite Element Method and the potential distribution due to the moving charge is then evaluated. The results are used to find the current passing through the rectangular pick-up electrodes. In conclusion the distribution of the total current in the electrodes as a function of the moving charge position and the layer conductivity and permittivity is given.

 191-194

Starczak M., Jakubiec W.:
Optimisation of Measuring Strategies in Coordinate Measuring Technique

Abstract: The guidelines for supporting software for optimal measurement strategy choice have been presented. The system of typical measurement tasks classification has been built. Each task has been characterised by determining the possible measurement strategies set. The conditions of performing measurements as well as the specific features having the possible influence on the measurement strategy have been taken into consideration. The example of steering gear case has been presented.

 195-198 Otomanski P.:
Using of Regression Method to Calculate Transformation Equation of Integrated Humidity Sensors 

Abstract: Results of experiments concerning humidity measurements have been presented in the paper. Integrated humidity sensors were used for the experiments, which transformed the value measured into a corresponding capacity. The structure of a measuring system was described, and the requirements concerning particular elements of the measuring track were defined. Using the regression method, an analytical equation was modelled, combining the output capacity value of the sensor with the examined humidity changes. With the use of the experimental results as well as the least square method, the values for the above equation.s parameters were determined. The confidence interval for each ordinate with the assumed probability 1- in the examined range of humidity changes was also determined.

 199-202

Adamski W., Kitliński M.:
On Measurements Applied in Scientific Researches of Microwave Heating Processes

Abstract:   Microwaves frequencies occupy the three decades of the electromagnetic spectrum (300MHz to 300GHz) that lie between VHF radiowaves and the far infrared. Their application fall into two categories, depending on whether the wave is used to transmit information or just energy. The first category includes terrestrial and satellite communication links, radar, radioastronomy, microwave thermography, material permittivity measurements, and so on. In all cases, the transmission link incorporates a receiver whose function is to extract the information, that in some way modulates the microwave signal. The second category of applications is the subject of this paper. As a whole it is called  a microwave heating. Here, there no modulating signal and the electromagnetic wave interacts directly with solid or liquid materials known as lossy dielectrics, among which water is of particular interest.

 203-206

Laurinavichus L., Novickij J., Filipavichus V.:
The Accuracy of Pulsed Magnetoplasma Interferometer Measuring Electrical Properties of Semiconductors

Abstract: The magnetoplasma interferometer with pulsed magnetic field source and its measurement accuracy are described. The total accuracy of concentration and mobility measurements free charge carriers depends on oscillations amplitudes and magnetic induction relative errors in general. Also it was determined that magnetoplasma beam spread is influenced on mobility accuracy and correction coefficients should be introduced to mobility formula.

 207-209

Jankauskas Z., Laurinavichus L.:
The Ring-Shape Antenna Modelling and Diffraction Measurements

Abstract: Existence of Gaussian electromagnetic beams in magnetized solid-state plasma provides the possibility for modelling the ring – shaped antenna with the dimensions much smaller ( 20 times) than the real object. The direction diagram and the angle of diffraction in this case may be measured in laboratory instead of field works.

 211-214

Nozdrzykowski K., Kuźniewski B.:
A Modernised Method of Measuring Crankshaft Strain Caused by Bearing Errors
Abstract: The article presents a new method of measuring crankshaft strain caused by bearing errors. These measurements are applied to evaluate the placing of the crankshaft in the engine.s body and to make a possible correction of the bearing setting. It has been described how the measurements were performed, and the results have been analysed and interpreted.

 215-218

Odon A.:
Processing of Signal of Pyroelectric Sensor in Laser Energy Meter
Abstract: In this paper the principles of measuring the energy of pulse light sources (especially pulse lasers), using pyroelectric sensors, are presented. The theoretical principles of operation pyroelectric sensors are described, as well a conversion system of pyroelectric sensor signal, enabling to reduce the influence of acoustic, thermal, and electromagnetic interference, influencing the sensor.

 219-222

Yurschevich V., Lomov S., Jankovskis J.:
Measurement of Self-Capacitance for Windings on High-Permeability Ferrite Cores
Abstract: Two methods of self-capacitance determination for windings on high-permeability ferrite cores are described. The first one is connected with the measurements on three frequencies, the second - with the measurements on a single frequency with and without additional capacitance. The methods are free from error associated with frequency and amplitude dependencies of the complex magnetic permeability components of ferrites. The potentialities of these methods are shown by data obtained for measuring windings (single-layer windings on toroidal cores) which are broadly used in magnetic measurements. In such a complicated case when the components of complex magnetic permeability are strongly frequency dependent, the offered methods ensure the acceptable accuracy of measurements even for small self-capacitance (in order of 1 pF).