This electronic device will be used to supply measuring circuits during calibration and inspection of measuring transducers of electro-energetic quantities, instruments, electronic protections and electricity meters. It will be very useful as a device to simulate the different ways of loading in electro-energetic network. The incorporated electronics will assure high stability of the set electric quantities, which is especially important for calibration and inspection of digital and etalon instruments.
In the present paper is presented a method for on-line narrow spike detention. The method consists of successive derivations of the signal till the only event remains significant in the sequence.
In the paper a new and original FEM-3D approach to the analysis and design of 20 kV combined current- voltage instrument transformer is given. For the complex study of the electromagnetic field phenomena in the compound configuration with two non-linear magnetic cores of this instrument transformer the finite element method in the three-dimensional domain is used. The FEM-3D derived results will be applied for calculation of the magnetic field distribution in the 3D domain, as well as for the determination of the leakage reactances of the transformer winding. This enables metrologically...
In the last years the current and voltage distortion in distribution systems has increased, because of the large number of loads, which draw non-sinusoidal currents. The usual measurement methods cannot provide any information about the source of harmonic distortion in a given metering section. Different measurement methods are therefore searched for. The most discussed methods are generally based on the decomposition of voltages and currents into Fourier series. This paper presents a different method for singular or total harmonic sources detection in power systems, based on the...
In the last years the increased interest about power quality, forced international working groups to define new standards for testing and measurement techniques applied to power systems. A particular attention has been paid to harmonic and interharmonic measurements for the well-known problems related to different power equipments. Considering the actual state of instrumentation technology, these standards assumes that only instruments using the Discrete Fourier Transform (DFT) are likely to be designed. Moreover, also if strictly speaking the concepts for distortion analysis can be applied...
The report presents the sources of uncertainties, met during medical measurements. They are the results of using measuring method, electromedical instrument measuring features and the form of biomedical standard (predicted value). Biological changeability of biomedical object plays the main role
Extracting three-dimensional information from two-dimensional image coordinates acquired by video cameras is a essential problem in computer vision. Prerequisite is a camera calibration procedure. For the purpose of camera calibration both linear and iterative techniques have been developed. The iterative methods utilize non-linear camera models, i.e. non-linear search technique. Three different popular non-linear search techniques (Newton method, Gauss-Newton method, Levenberg-Marquardt method) were chosen and compared in order to find out which one gave the best results for the purpose of...
In the paper a measurement system for the carotid occlusion volume, based on 3-D ultrasound imaging is proposed. The system has been designed taking into account two main tasks: computational effort and measurement accuracy. The analysis of the uncertainty of the whole measurement chain and first xperimental results on carotid images are given.
Possibilities for quantifying the ferromagnetic particle contamination in human lungs with help of a rf SQUID system were studied. A tool for the analysis of the quantification of the measured data was developed. Conditions for the calculation of the particle concentration in human lungs from the measured remanent magnetic induction were established. The theoretical calculations were verified by measuring on physical lung models. The illustration of the method and a rough estimation of the concentration were carried out on an arc welder, with evidently contaminated lungs. The work also...
Compounds can be classified by infrared spectroscopy through the variation of their transmittance, reflectance or emittance with frequency. At the present time, measurement of the transmittance spectrum of a sample is the usual means of identifying a material; reflectance spectroscopy is used infrequently while emission spectra are hardly ever measured. One of the principal reasons for the unpopularity of infrared emission spectroscopy is the experimental difficulties involved, especially when the sample is only able to be heated to very slightly above room temperature. In this case the...