IMEKO Event Proceedings

Page 735 of 748 Results 7341 - 7350 of 7479

Gianni Togliani
Virtual DMT: An Opportunity for Pile Design?

The DMT results are rarely used for piles design, probably because its diffusion and popularity are still limited although DMT is in use for a long time. Conversely CPTu are much more popular and often used to this purpose: this is the reason why a large concerned database is available where it is possible to get the CPTu/DMT conversion experienced in recent years. This was done for two well-documented cases [a bored pile in Santa Cruz (Bolivia) and a driven pipe pile in Sandpoint, (US)] with promising results.

Valeriy Borikov
VIRTUAL ELECTROLYTE CONDUCTIVITY ANALYZER FOR MICROPLASMA OXIDATION PROCESS CONTROL

This paper presents both hardware and software of virtual system for conductivity measurement of electrolyte solution. The distinctive feature of the system is its application for the concentration control of an electrolyte solution component during microplasma oxidation process which is characterized by the conductivity in the range from 0.1 S/m to 30 S/m. The analyzer has virtual control panel and based on module measurement system of National Instrument PXI standard. Structure and main principles of constructing the system components are described. Its technical and metrological parameters are given.

D. Kovacevic, S. Skundric, B. Dimitrijevic
VIRTUAL ELECTRONIC SCALES

The paper presents a new concept of virtual electronic scales (VES) conceived as a PC peripheral. The traditional approach, “specific scales for specific application”, has dominated the development and production of both mechanical and state-of-the-art electronic scales. The main aim of this paper is to promote a PCbased approach – electronic weight scales as a virtual instruments. The paper offers a detailed presentation of originally developed hardware and software structures of VES called Soft Scales, based on strain-gauge load cells, of 2 ... 200 kg measurement range, accuracy class III, up to 10,000 scale intervals. Finally, a list of specific applications and realisation of both trade scales and body mass index measurement sistem as a virtual instruments, together with a brief measurement-technical comparison between the classical and PC-based approach are presented.

Cristian Zet, Olga Plopa,Cătălin Damian, Cristian Foşalău
VIRTUAL IMPEDANCE SPECTROSCOPY FOR ELECTROLYTICAL CELLS

Impedance spectroscopy play an important role in fundamental and applied electrochemistry and materials science. In a number of respects it is the method of choice for characterizing the electrical behavior of systems in which the overall system behavior is determined by a number of strongly coupled processes, each proceeding at a different frequency. The paper presents a virtual instrument and the associated hardware that allows to perform the impedance spectroscopy on an electrolytical cell. It is aimed for studying phenomena (charge transfer, difusion or electrode polarisation) that occur while growing nanowires in polycarbonate templates. The hardware consists of a NI PCI6111 data acquisition board and external analog front end (programmable current to voltage converter and programmable mixed AC – DC voltage generator). The software is developed in Labview and allows to perform the impedance spectroscopy and to save the data on a file. With a different software, the system can be used also for electrochemical deposition or for etching of the polymer membranes with ion tracks. Detailed schematic description is presented, together with experimental results.

Gregor Geršak, Janez Humar, Dušan Fefer
VIRTUAL INSTRUMENT – THE NMR MAGNETOMETER

In this paper a Nuclear Magnetic Resonance magnetometer (NMR) in a form of a LabVIEW Virtual instrument (VI) is proposed. The heart of the magnetometer remains the marginal oscillator with a proton sample. The magnetic resonance signal and all other auxiliary signals are generated and controlled by a set-up composed of a digital counter (for resonance frequency measuring), a VXI system (for the modulation signal generation and for the sampling of the oscillator output), a programmable DC voltage source (for oscillator frequency control) and a personal computer controlling the measurement. The virtual magnetometer was built and preliminary test measurements were done. The measuring results of the determination of a field-coil coilconstant showed that the virtual NMR magnetometer’s readings were comparable to the classic NMR magnetometer’s within 5·10-4.

E. Lunca, A. Salceanu, S. Hanganu, C. Donciu
VIRTUAL INSTRUMENT AIMING TO EXTEND THE CAPABILITIES OF THE SPECTRUM ANALYZERS

The paper presents a virtual instrument for measuring the insertion loss, signal-to-noise ratio, carrier-to-noise ratio and frequency response. Since most of the spectrum analyzers are equipped with a GPIB or RS-232 interface, here demonstrate that LabVIEW graphical environment represents the proper tool to develop such applications. Sometimes, instrument producers provide specific software, but using LabVIEW some additional costs can be eliminated by user developed software.

M. Numminen, O. Aumala
VIRTUAL INSTRUMENT AS AC MEASUREMENT TRAINING TOOL

Software can be used to help students to learn the use and properties of common electrical measurement devices. Virtual instruments are applied here to realize a self-study package. Alternating current measurements can be trained with a virtual signal generator and different types of virtual multimeters. The paper presents educational needs clarified by study diaries as well as the virtual instruments developed.

Marco Ricci, Luca Senni, Pietro Burrascano
VIRTUAL INSTRUMENT FOR AIR-COUPLED ULTRASOUND NDT APPLICATION BASED ON PSUEDO-NOISE SEQUENCES

A Virtual-Instrument for Air-Coupled Ultrasound Non Destructive Testing applications based on Psuedo- Noise Sequences is presented. The instrument is designed by means of the LabView software to manage and synchronise a digital input/output module and a virtual oscilloscope and to implement the digital processing required to fully exploit the characteristics of the coded excitation. The Signal to Noise Ratio enhancement assured by this technique with respect both Additive White Gaussian Noise and Quantization Noise is theoretically analysed and experimental verified.

Constantin Sarmasanu, Emil Vremera, Lucian Nita, Valeriu David
Virtual instrument for comfort factor measurement

This paper focuses on a description of the comfort by means of the temperature-humidity comfort index. In the attempt to describe this complex phenomena, those related to the human perception, for temperature and humidity estimation, we propose to use words of natural language. This linguistic description is not so accurate and also subjective than the numeric one obtained through usual sensors, but it is easily understood by human beings even if the concept is abstract due to it geographical context dependence. Finally, an aggregation of temperature and humidity measurements performed by a virtual symbolic sensor is presented for the qualification of the comfort inde

Vladimir Dimcev, Zivko Kokolanski, Dimitar Taskovski
Virtual Instrument for Power Quality Research

In the paper a virtual instrument for power quality measurement and research is proposed. The instrument is divided in several modules which provide generation, measurement and recording of the typical power quality (PQ) disturbances such as: harmonics, voltage dips, interruptions, flicker, unbalance etc. The virtual instrument allows setting different measurement parameters which expands its capabilities for research work. To perform real-time monitoring a prototyped signal conditioning circuit has been developed.

Page 735 of 748 Results 7341 - 7350 of 7479