A model for the crosstalk between two twisted pairs caused by splices, is proposed. The model will allow the crosstalk to be calculated in any case where splices exist in a transmission line. The expressions are then evaluated by measurements on a lab-produced splice and the total influence of the splices on the total crosstalk is evaluated, in order to see if the crosstalk caused by the splices is relevant compared to the standard crosstalk.
This paper presents the problems relating to the measurement of power system loop impedance in present day low voltage networks particularly in presence of voltage disturbances. The paper discusses the main sources of loop impedance measurement errors such as: the difference in impedances arguments, transients in tested circuit and the distortion of the voltage waveform in the measurement point. The conditions how to minimize measurement inaccuracy are also given. Example of loop impedance measurement errors are presented in the form of graves for different parameters of the tested circuit.
The aim of this work is the creation of a virtual instrument for the management of an experimental set-up in which the electronic instruments are interchangeable. This is possible using IVI drivers (National Instruments). In this way the software system becomes independent of the chosen hardware.
Presented paper concerns the problem of signal period estimation improvement by means of the wavelet coefficients. In particular, the interpolation based on the wavelet coefficient has been proposed for this aim. The method does not require virtually any additional computational power of measurement device, under assumption that the wavelet transform has been implemented for waveform analysis. In the paper results of experimental research have been presented and its merits as well as shortcomings have been discussed.
This paper presents results of investigation on influence of stress from the external forces on the sensitivity of the fluxgate sensor with 80% Ni-Permalloy P-80M ring core. Stress was applied in two directions: in the direction of diameter of the ring or in perpendicular direction to the magnetising field in the ring core. The influence of mechanical stress from the external forces on the magnetic properties of this ring core was measured. Then results of this testing were used in computer simulation of the influence of stress on the output signal of the fluxgate. The results confirmed,...
Set of filters is required for the analysis of sound and vibration signals usually composed of different elements. The designing process of so-called 1/1 octave and 1/3 octave digital filters and their implementation in the digital signal processor, working in the real time system, is shortly presented. The obtained exemplary frequency characteristics are given.
Original electrical methods of piled up dikes status monitoring are described. Using these methods, progress of water infiltration and deformations inside of the dike body can be indicated. Some results are shown and discussed.
The measurement of electrical quantities in electronic circuits is inscribed in the non-parametric world for a long time. Multimeters, Oscilloscope and Network Analysers are the preferred tools used by engineers. Parametric identification allows a new step in circuit characterization. This approach opens new perspectives in the process of electronic circuit’s design. The present paper presents a solution to the problem of parametric characterization. To allow the simulation and validation of the results a new simulation tool is also presented. The proposed simulation solution uses modified...
In the paper the performance of a portable data acquisition system under radiated electromagnetic disturbances is investigated, in order to find out if and how its peculiar characteristics change with respect to the ones measured in absence of electromagnetic field. The analysis is carried out by means of experimental tests, subjecting the system under test to the threats considered by the IEC-61326 standard and following the test procedures prescribed in the IEC-61000-4-3 standard. The results show that the electromagnetic influence can lead to a worsening of the tested data acquisition...
Internet users and Internet service providers are using all kinds of tools for monitoring the communication network. Most of the measurements are done by inserting simulated traffic into the network and observing network performances. When used to measure some time-sensitive applications, like Voice over IP (VoIP), these tools in coherence with some network configuration techniques can result with inaccurate measurement result. We discuss some of those configuration techniques and their influence on delay measurements, and introduce possible solutions.