| MEASUREMENT SCIENCE REVIEW Volume 7, Section 3 Main Page | |
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SECTION 3 Download
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| Measurement of Physical Quantities | |
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No. 1 |
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| 1-10 |
Chugui Yu.V.: Optical Measuring Systems and Laser Technologies for Scientific and Industrial Applications REVIEW ARTICLE
Abstract: The novel results of the
R & D activity of TDI SIE SB RAS in the field of the optical measuring
technologies, as well as laser technologies for solving actual problems are
presented. The metrological characterization of a perspective Fresnel method for
high precision measuring the dimensions of objects is investigated. An
optoelectronic noncontact method using diffractive optical element for the 3D
inspection of article holes is presented. For permanent noncontact bearing
position inspection of oil-drilling platforms on Sakhalin
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| 11-14 |
Bartkevičius S., Novickij J.:
The influence of
pulsed magnet heating on maximal value of generated
Abstract:
The influence of pulsed magnet heating on maximal value of generated magnetic
field is described. The operation of pulsed generator consisted of capacitor
bank, thyristor switch and wire wound pulsed inductor is analyzed. The maximum
value of generated magnetic field and pulse duration of pulsed magnet is limited
by Joule heating and mechanical stresses. Using Matlab Simulink software the
flexible model for simulation of
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| 15-18 |
Štofanik V., Markovič M., Boháč V., Dieška P., Kubičár Ľ.:
RT-Lab - the Equipment
for Measuring Thermophysical Properties by
Abstract:
The paper introduces novel equipment RT-Lab for measuring thermophysical
properties of various materials by means of the transient methods we have
developed in our laboratories. The entire measuring process can be realized by
the RT-Lab. The equipment can operate in several measuring regimes and different
transient methods. Functionality of the RT-Lab was verified by measurement of
the thermophysical properties of the standard material BK7 using pulse transient
method. The RT-Lab replaced the electronic unit RT 1.02 that for its operation
required two additional expensive equipments, the programmable power source
(KEPCO ABC 15-7 DM) and the precise multimeter (KEITHLEY-2010).
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| 19-23 |
Barauskas S., Jankauskas Z., Kvedaras V., Suslov A.:
Measurement of Charge
Density and Mobility in Semiconductors in the
Abstract:
In the semiconductors when the strong constant magnetic field H is applied the
nondissipative
Hall currents appear and helicon magnetoplasmic waves may be excited. The
semiconductor sample becomes partially transparent under these conditions. In
the case of
resonance the transparency coefficient has maximum or minimum depending of
resonance
number. For fixed values of H and excitation frequency ω the charge density and
mobility
may be found. Measurements were conducted in the range of radio frequencies
10-2000 MHz,
and magnetic fields 0-32 Tesla for n-InSb and n-Ge.
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No. 2 |
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24-27 |
Boháč V., Dieška P., Kubičár Ľ.: The Heat Loss Effect at the Measurements by Transient Pulse Method
Abstract:
In this paper we bring the new
physical approach to a solution of deficiency in a large amount of testing
material. It is a real problem of finite geometry of the specimen that
additional effects harm the efficiency of standard way of the measurement
evaluation. Three different models used for data evaluation are discussed in
this paper. As a model material a PMMA specimen was used. There are discussed
two approaches how to avoid the problem of heat loss effect in real experiment.
The ideal one that assumes infinite geometry in a model and the limited time of
recorded data used for parameters evaluation as the temperatures recorded at
short times are not influenced by heat loss effect. The new model introduces
next parameter - a heat transfer coefficient that represents heat loss effect
from the free sample surface. Thermophysical data are given also numerically and
agree with recommended data within 6% for all discussed models.
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| 28-32 |
Hain M., Kawate E.:
An Optical Method for the
Measurement of Shape Deviations of Elliptical
Abstract:
The contribution deals with the fast optical method of shape deviations
measurement of elliptical mirrors. The method for the shape deviations
measurement utilises a scanned laser beam reflected from the elliptical mirror
surface and a digital CCD camera for the beam position measurement in focal
plane of the mirror under test. A mathematical evaluation including Fast Fourier
Transformation (FFT) of the measured data was used to evaluate the shape
deviations and waviness of the mirror’s surface. Results of the optical
measurement were compared with the data obtained from the CMM (Coordinate
Measuring Machine) measurement.
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| 33-36 |
Bittera M., Smieško V., Kováč K.: Effect of bundled power cable on radiated emission measurement
Abstract:
The paper deals with effect of
different types and different arrangements of power cables of equipment under
test to results of EMI measurements. It is because the cables attached to tested
equipment represent the potential sources of undesired radiation. The influence
of two- and three-wire power cables is surveyed using numerical techniques based
on models that are verified by analytical calculation and measurement.
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No. 3 |
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| 37-41 |
Zhang J., Regtien P.P.L.: Illumination methods for optical wear detection Abstract: The paper presents some results of a study on optical wear detection. The focus of the paper is on the illumination, to optimize the contrast of the images. Various illumination methods are compared: bright field versus dark field illumination, and various kind of light sources: laser light, diffuse light and ring-light. Keywords: wear detection, illumination
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| 42-46 |
Bittera M., Kováč K., Hallon J.: Measurement of semi-anechoic chamber using modified VSWR method above 1 GHz
Abstract:
Most of alternative test places as semi-anechoic chambers are designed to use
them for EMI measurement in frequency range 30 ÷ 1000 MHz. Nowadays it is
necessary to measure radiated emission also at higher frequencies in some cases.
However, no valid standard exists to determine the process of their
verification. In this paper modified site VSWR method was used to obtain
behaviour and possible utilization of semi-anechoic chamber of EMC Laboratory
for measurement at higher frequencies up to 10 GHz in measuring distance 1 m.
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No. 4 |
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47-50 |
Stein G. J., Chmúrny R., Rosík V.: Measurement and analysis of low frequency vibration Abstract: Low frequency vibration occurs especially in ground transportation, either as a cause in adjacent environment or within the vehicle itself. The piezoelectric accelerometers commonly used for vibration measurement are not suitable, hence other sensors capable of measuring accelerations down to sub-hertz region have to be used. Based on some previous experience with MEMS acceleration sensors a three-axial MEMS accelerometer was interfaced to a data acquisition unit. The digitised data were processed by scripts by Matlab® with the aim to discriminate between low frequency translatory acceleration and vibration acceleration. Some preliminary results of this endeavour are presented. Keywords: vibration measurement, MEMS accelerometer, vibration measuring system
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51-54 |
Töpfer S. C. N., Linß G.: Quality measures for optical probing in optical coordinate metrology Abstract: Typically measuring points in optical coordinate metrology are considered equally at the subsequent fitting of geometric elements, for example circle. This is due to the fact that no information regarding the related probing uncertainty of the individual measuring points is available. This paper outlines a novel approach for the determination of quality measures at the edge as a measure for the related probing uncertainty. The quality measures are based on the evaluation of the intensity characteristic at the edge, whose position is to be measured. The intensity characteristic is quantitatively evaluated on a scale of 0 to 100 equivalent to the range from excellent to very bad. Thereby five different criteria such as slope, width, form, noise and uniqueness of the edge are utilised. The overall quality measure is calculated as a weighted sum of the individual quality measures. The proposed quality measures have been applied at a number of different measuring objects. The experimental data prove the soundness of the new approach. The utilisation of the proposed quality measures results in a decrease of measuring uncertainty. Keywords: quality measures, edge quality, probing uncertainty, optical coordinate metrology
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No. 5 |
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55-58 |
Odon
A.: Circuit Breakers Timing Test System Abstract: The paper presents the construction and principle of operation of a designed and constructed meter for testing the operation times of three-phases circuit breakers. The measurement is performed by the digital time-pulse conversion method. The design is based on a micro-controller. The block scheme of the meter and principle of operation are given, along with the results illustrating the metrological parameters of the device. Keywords: circuit breaker timing tests, the operation times of a breaker, circuit breaker monitoring
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59-62 |
Bartl
J., Guttenová J., Jacko V., Ševčík R.: Circuits for Optical Frequency Stabilization of Metrological Lasers
Abstract:
Nowadays, the Slovak
National Length Standard is based on the HeNe laser. Its optical frequency
is stabilized by the saturated absorption method in 127I2 iodine molecules
with relative uncertainty 10-11. This solution is dominant in majority of
metrological institutes of the world so far [1]. The ground of long time
laser stability is in its thermally stable mechanical construction.
Optoelectronic feedback allows stabilizing the laser frequency precisely at
wavelength causing the saturated absorption in iodine vapour. This feedback
is controlled by signal of photodiode and action control element is the
piezo carrying the laser mirror. The operation principle and the arrangement
of diode laser differ from that of HeNe laser and therefore the application
of method mentioned above must be adapted to new conditions. This
contribution is aimed for design of electronic circuits Keywords: optical feedback, tuning frequency generator, saw tooth voltage generator
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No. 6 |
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63-66 |
Kawate
E., Tesar R., Hain M.: New Optical Measurements Realized by Oblique Incidence
Abstract:
An optical equipment has been developed, which is originated with two
mirrors shaped like an ellipsoid of revolution. Firstly it is found that the
pseudo Brewster angle for an absorbing substrate becomes small with
increasing a nonabsorbing film thickness. The thickness of a dielectric thin
film can be measured on a metal substrate in the visible region. Secondly a
plane-parallel plate serves as an interferometer and the coefficient of
finesse for an S-polarized plane wave increases with increasing an incident
angle. Thus the refractive
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67-75 |
Salahinejad M., Aflaki F.: Uncertainty Measurement of Weighing Results from an Electronic Analytical Balance
Abstract:
Uncertainty of a measurement result is a major issue in all fields of
measurement. Weighing is a critical step in any chemical laboratory and
analytical methods. It’s an important uncertainty sources in uncertainties
measurement in an analysis. In this paper we tried to present the influence
factors that affect in uncertainty Keywords: weighing, uncertainty measurement, non-linearity, electronic balance
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