MEASUREMENT SCIENCE REVIEW                         Volume 7, Section 3                 Main Page

 SECTION 3                           Download and print the front cover  ->>   VOLUME 7, 2007

  Measurement of Physical Quantities

 No. 1




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
coast (Russia) under extreme temperatures (± 40°C) we have developed optical-electronic method and system SAKHALIN. Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting, welding and surface micro profiling with ablation process (working range of 3 × 3 × 0.6 m3, positioning error less than 10 μm). Safety of Russian nuclear reactors takes 100 % noncontact 3D dimensional
inspection of all parts of fuel assemblies, including grid spacers. Results of development and testing the specialized high productive laser measuring machine, based on structured illumination, for 3D inspection of grid spacers with micron resolution are presented.
Keywords: optical inspection, structured light and shadow methods, laser technology, safety



Bartkevičius S.,  Novickij J.:

The influence of pulsed magnet heating on maximal value of generated
magnetic field

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
thermodynamic processes in pulsed magnet is done. Calculated results of maximal value and distribution of magnetic field are verified experimentally and the acceptable compliance is achieved using calibrated array of four pick up inductive coils for measurements of axial magnetic field and a current shunt for pulsed current measurements.
Keywords: pulsed magnetic field, wire wound magnet, Joule heating, pick up inductive coil



Štofanik V.,  Markovič M.,  Boháč V.,  Dieška P.,   Kubičár Ľ.:

RT-Lab - the Equipment for Measuring Thermophysical Properties by
Transient Methods

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).
Keywords: Transient methods, Thermophysical properties



Barauskas S., Jankauskas Z., Kvedaras V., Suslov A.:

Measurement of Charge Density and Mobility in Semiconductors in the
Strong Magnetic Field

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.
Keywords: n-InSb, n-Ge, magnetic fields.


 No. 2




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.
Keywords: pulse transient method, thermophysical properties, heat loss effect



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.
Keywords: contactless measurement, elliptical mirror, shape deviations, waviness



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.
Keywords: EMI measurement, power cable, numerical simulation


 No. 3




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



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.
Keywords: semi-anechoic chambers, site VSWR, verification of test place


 No. 4




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



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


 No. 5




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



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
providing for this new approach.

Keywords: optical feedback, tuning frequency generator, saw tooth voltage generator


 No. 6




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
index of a thin film on the plate can be measured in the millimeter wave region.
Keywords: STAR GEM, GAEA, pseudo Brewster angle, absolute reflectance



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
measurement of a mass determination. Technical specifications of a balance such as: Readability, Repeatability, Non-linearity, Sensitivity Tolerance, Temperature Coefficient of Sensitivity and effects of environmental factors such as: air humidity, air pressure and air buoyancy were estimated. In the absence of some disturbance
factor like water adsorption phenomena, evaporation, magnetic and electrostatic effects, the measurement uncertainty for an electronic balance in our laboratory is in the 10-4 to 10-3 range (100 to 1000 ppm).

Keywords: weighing, uncertainty measurement, non-linearity, electronic balance