MEASUREMENT
SCIENCE REVIEW Volume 1,
Section 3.
Main
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Measurement of Physical Quantities |
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1-4
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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.
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5-8
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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.
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9-12
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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.
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13-16
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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.
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17-20
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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.
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21-24
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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.
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25-28
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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.
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29-32
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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.
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- 33-36
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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).
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