IEEE Transactions on Instrumentation and Measurement

Coaxial straight-wire resistors have been constructed with the purpose of improving comparisons between resistors, capacitors, and inductors in the audio-frequency range. The design is based on the principle that a coaxial line with a cylindrical shield can be described by relatively simple equations for the real and imaginary parts of the impedance. The resistors, with values at and above 100 &Om... View full abstract»

This paper provides the theoretical basis for the measurement of reactive and distortion powers from the wavelet transforms. The measurement of reactive power relies on the use of broad-band phase-shift networks to create concurrent in-phase currents and quadrature voltages. The wavelet real power computation resulting from these 90° phase-shift networks yields the reactive power associated wi... View full abstract»

This paper describes a measurement system enabling the complete real-time characterization of the wideband radio channel. The system is based on a wideband radio channel sounder and a spherical antenna array, and it aims to describe the three-dimensional (3-D) spatial radio channel seen by the mobile terminal, including polarization. This information is highly valuable in designing antennas for mo... View full abstract»

The paper deals with a test method, based on the generation of signals with known and pre-assigned harmonic content, for calibrating measurement devices to be used under nonsinusoidal conditions. The attention is concentrated on selecting the most suitable waveforms for the characterization of measurement instruments, by considering both the amplitude and the relative phase of the different harmon... View full abstract»

A noise-insensitive technique for the discrimination between speech and voice-band data transmissions over a telephone-type system is presented. The proposed procedure combines together the evaluation of some meaningful parameters extracted from the observed speech or data communication signal, with an analysis of the statistical moments associated with these parameters. In this way, the discrimin... View full abstract»

In this paper, we present a portable, battery-operated, three-dimensional magnetic microsystem (magneto-dosimeter), intended for monitoring the workers' exposure to magnetic fields in particular working environments, such as hospitals or physics laboratories. The proposed microsystem is based on a multichip module containing three equal channels for the three components of the magnetic field measu... View full abstract»

This paper presents a low-cost analog test system with diagnosis capabilities. The tester is able to detect faults in any linear circuit by learning a reference circuit behavior in a first step, and comparing this behavior against the output of the circuit under test in a second step. For a faulty circuit, a third step takes place to locate the fault. The diagnosis method consists in injecting pro... View full abstract»

Three-layered electrode structures are often employed in multiple-electrode capacitive position sensors. Even when advanced algorithms and well-designed guarding electrodes are used, the electric-field-bending effect is still one of the major contributors to the nonlinearity of capacitive position sensors. In this paper, the effects of electric-field bending on linearities of five capacitive linea... View full abstract»

The paper deals with a measurement system based on a low-cost eddy current probe for nondestructive testing (NDT) on conducting materials aimed at reconstructing the shape and position of thin cracks. The magnetic probe is characterized, highlighting good repeatability, linearity, and overall accuracy. A number of different measurement approaches are investigated, in order to choose the most appro... View full abstract»

Evolution and cost of measurement equipment, continuous training, and distance learning make it difficult to provide a complete set of updated workbenches to every student. For a preliminary familiarization and experimentation with instrumentation and measurement procedures, the use of virtual equipment is often considered more than sufficient from the didactic point of view, while the hands-on ap... View full abstract»

In recent years, advances in integration fabrication technologies prompted IC designers to move more analog circuitry onto what had been entirely digital chips, making the verification problem for the entire chip more difficult. This paper presents a detailed case study of using the oscillation test methodology to test an active low pass filter. We highlight some of the difficulties and shortcomin... View full abstract»

Neurofuzzy approaches are very promising for nonlinear filtering of noisy images. An original network topology is presented in this work to cope with different noise distributions and mixed noise as well. The multiple-output structure is based on recursive processing. It is able to adapt the filtering action to different kinds of corrupting noise. Fuzzy reasoning embedded into the network structur... View full abstract»

RFX is a magnetically confined fusion experiment in operation since 1992 in Padova, Italy. Analysis of the magnetic field is essential for the safe operation of the machine and the understanding of high-temperature plasma dynamics. Both of these issues require an accurate electromagnetic diagnostic system. In this paper, after a discussion of the problems related to magnetic measurements in fusion... View full abstract»

This paper presents a simple approach to a dry calibration procedure for the electromagnetic flowmeter for both conducting and nonconducting open-flow channels. The author focuses on two main problems: variable water level in the measurement zone and variable water or ground conductivity and their influence on a flow signal. Based on the existing numerical model of electromagnetic flowmeter, the a... View full abstract»

In this paper, the required measurement time to measure a transfer function with a specified accuracy is analyzed. The waiting time that is needed to balance the transient induced errors against the noise errors is calculated. This allows one to decide under what conditions broad-band measurements are faster than stepped sine measurements View full abstract»

A broadband radio interferometer to investigate the location of fast-moving electromagnetic (EM) sources emitted from lightning discharges has been designed. A sequential triggering technique was applied to the system for recording the data of broadband electromagnetic pulses from 25 to 250 MHz. Once the electromagnetic pulse is detected and its amplitude exceeds a threshold level, the triggering ... View full abstract»

A novel technique for measuring integrated circuit (IC) package shielding effectiveness is presented. The technique is based on radiated field measurements performed with an integrated circuit antenna in a Gigahertz transverse electromagnetic (GTEM) cell. A thorough test procedure which takes into account all possible field contributions is proposed. The technique is simple to implement, cost effe... View full abstract»

In this paper, the authors discuss the use of deterministic and stochastic dither sequences in analog-to-digital conversion including data postprocessing. Properties of both types of dither signals are highlighted, and a performance comparison is carried out by considering residual bias and mean square error. It is concluded that superior performance can be attained by deterministic dither in term... View full abstract»

With resampling, a regularly sampled signal is extracted from observations which are irregularly spaced in time. Resampling methods can be divided into simple and complex methods. Simple methods such as Sample and Hold (S and H) and Nearest Neighbor Resampling (NNR) use only one irregular sample for one resampled observation. A theoretical analysis of the simple methods is given. The various resam... View full abstract»

A small, high-resolution paramagnetic susceptibility thermometer was developed using a GdCl3 paramagnetic salt. The device uses a superconducting quantum interference device (SQUID) magnetometer to determine the temperature dependent magnetization of the salt in a magnetic field. The magnetic field is provided by a pair of small samarium cobalt permanent magnet disks situated inside the... View full abstract»

This paper is on digital processing of data acquired by means of low-resolution spectrometers. A procedure for calibration of such spectrometers is proposed which provides parameters of operators for correcting effects of imperfect spectrometric hardware. The procedure, based on the use of a genetic algorithm of global optimization, is studied using both synthetic and real-world data, viz, it is u... View full abstract»

This paper proposes and compares two methods for the automatic detection of force adaptation disturbances from recorded kinematic and kinetic signals of periodic hand movements. Line-oriented spectrum and cross-correlation analysis are examined as methods for the evaluation of periodic acceleration and grip force hand movement signals, thereby opening novel ways for the automatic assessment of for... View full abstract»

A new design of optical electric-current sensor based on the Faraday effect is proposed and demonstrated experimentally. The sensor probe is a precisely cut glass prism with a high reflection coating on the base surface at the far end. Inside the prism, the light beam is allowed to bounce up and down at the critical angle and retrace its path back by the reflection coating. The sensor demonstrated... View full abstract»

The Electricity Division at the NIST has developed the capability to characterize capacitance and dissipation factor for four terminal-pair (4TP) air dielectric capacitors at frequencies from 1 kHz to 10 MHz. The method involves single-port network analyzer impedance measurements at frequencies from 40 MHz to 200 MHz and capacitance measurements using a precision 1 kHz capacitance meter. A mathema... View full abstract»

This paper presents a novel application of neural network modeling in the optimization of sensor locations for the measurement of flue gas flow in industrial ducts and stacks. The proposed neural network model has been validated with an experiment based upon a case-study power plant. The results have shown that the optimized sensor location can be easily determined with this model. The industry ca... View full abstract»