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Page 808 of 936 Results 8071 - 8080 of 9356

Marek Niedostatkiewicz, Grzegorz Lentka
Frequencies selection for accelerated CNLS parameter identification of anticorrosion coatings

The paper presents modified CNLS impedance spectrum fitting method of parameter identification of technical objects. The number of test frequencies is reduced to the number of parameters and the test frequencies are set according to various criteria. As a test object, the model of anticorrosion coating has been chosen. The simulated identification results are discussed in terms of identification measurement time reduction and method accuracy.

Romuald Masnicki, Janusz Mindykowski
Quality improvement in measurement channel including of ADC under operation conditions

The possibility of using of the IEEE STD-1057 and STD-1241 standards for measurement channel features estimation in operation conditions is discussed. The standards concern the test methods and circuits for the devices containing ADC in laboratory conditions and cannot be simply applied in the instrument under operation conditions. Some remarks concerning the specificity of such conditions and range of applicability of standards are presented. The results of examining of selected test signal sources are discussed.

Mariana Milici, Dan Milici, Mihai Cretu
Temperature Measurement in Distributed System for Building Management

The paper present a system for management building based a compatible PC computer that communicates through a RS-485 serial protocol with the development board with microcontroller. The development boards are placed on the level of each building floor. These development boards take the signal from sensors placed on the level of each room and achieve the command function based on an independent algorithm, commanding by case the corresponding central heating or cooling plant.

Dan Milici, Mariana Milici, Stefan Gh. Pentiuc
Electrocardiographical Signals Parameters Measuring

This paper present a virtual instrument using for analysing a electrocardiographical signals. An interesting analisys can be made having on the base the graphical representation of samples series depending on this derivative, using a wavelette transform or fractal analysis.

Pedro M. Ramos, Tomáš Radil, Fernando M. Janeiro, A. Cruz Serra
DSP Based Power Quality Analyzer using New Signal Processing Algorithms for Detection and Classification of Disturbances in a Single-phase Power System

This paper describes the prototype of a power quality analyzer designed for real-time detection and classification of disturbances that occur in a single-phase power system. The previously developed algorithm for disturbance detection and classification was improved and implemented in a standalone DSP based analyzer. Its performance was verified during long term monitoring of the power system.

Pedro M. Ramos, Fernando M. Janeiro, Mouhaydine Tlemçani, A. Cruz Serra
Implementation of a DSP Based Impedance Measurement Instrument Using Ellipse Fitting Algorithms

In this paper, the DSP implementation of an impedance measurement instrument based on ellipse fitting algorithms is described. The system prototype is based on a commercial DSP kit with few external electronics for baseline assessment and requirements definition. The implemented system is tested for impedance magnitudes from 100 Ω up to 15 kΩ, phases in the ±90º range at 1 kHz measuring frequency with extremely good results.

Pasquale Arpaia, Pasquale Cimmino, Fabrizio Clemente, Carmine Romanucci
A Microcontroller-based Instrument for Prostheses Osseointegration Measurement by Electrochemical Impedance Spectroscopy

A method based on Electrochemical Impedance Spectroscopy (EIS) for the diagnosis of prosthesis osseointegration was proposed by the Authors in previous works. In this paper, the design, the implementation, and the metrological characterization of a microcontroller-based prototype conceived as a stand alone instrument to be used for in-vivo clinical applications are presented. The preliminary experimental results of laboratory evaluation are presented.

Camelia Petrescu, Lavinia Ferariu, R.Olaru
Genetic Algorithm Combined with Finite Element Method for Optimum Design of Ferrofluid Actuator

This paper presents a case study concerning the optimization of a DC ferrofluid actuator designed to transmit small pressures, using genetic algorithms. The optimization problem consists in finding the values of some mechanical parameters of the actuator as well as those of the magnetic permeabilities of the device components, that render a maximum equivalent force. The magnetic field inside the actuator is determined using the finite element method and the force acting on the flexible parts is calculated using Maxwell’s magnetic tensor.

U. Pogliano, C.G. Bosco, M. Lanzillotti, D Serazio
Ac-dc transfer standard shunts for frequencies up to 1 MHz

A new type of coaxial shunt for high frequency ac-dc current transfer standards has been designed. The structure of the shunts with nominal current from 100 mA to 5 A are made of a disk with two coaxial conductive layers in one side. SMD resistors are soldered in parallel between the two layers. Two conductive screens are applied in both side of the disk. In order to reduce stray effects, the structure has ideally no common magnetic interaction between the input current and the output voltage and practically a very low section where the magnetic field is confined, so allowing a flat response in a wide frequency range.

Warsza Zygmunt Lech
Accuracy measures of the four arm bridge of broadly variable resistances - Part 1: Backgrounds, general case of four variable arms

After short introduction the open circuit output voltage of four-arm resistance (4R) bridge supplied by current or voltage is given. Normalized forms of its current to voltage and voltage to voltage open circuit transmittances are defined. The simplified description of accuracy of the broadly variable resistance by instantaneous, limited and random errors of its initial value and of increment is introduced. Borders (the worst cases) of the field of its possible error values are found for constant values of both this limited errors. Accuracy measures of current to voltage transmittance, i.e. instantaneous and limited errors and mean square random measures (probabilistic errors or uncertainties) are discussed in detail for general case of arbitrary variable all bridge arms. Basic formulas together with their equivalents for voltages transmittance are completed in the table 1. Literature is included. Accuracy description of other common in practice particular cases of the 4R bridge and example of its application for temperature sensors Pt 100 are described in the part 2. Final conclusions are also there.

Page 808 of 936 Results 8071 - 8080 of 9356