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Instrumentation and Measurement, IEEE Transactions on

Issue 3 • Date Jun 2000

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Displaying Results 1 - 25 of 39
  • Wirelessly interrogable magnetic field sensor utilizing giant magneto-impedance effect and surface acoustic wave devices

    Page(s): 648 - 652
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB)  

    A micro-magnetic field sensor is developed using the giant magneto-impedance (GMI) effect in a 30 μm diameter amorphous FeCoSiBNd wire of zero magnetostriction. Surface Acoustic Wave (SAW) devices are described as passive, radio requestable sensor devices. A new type employs the electrical load of the SAW device by the impedance of conventional sensors. In order to develop a wirelessly interrogable magnetic field sensor, the combination of GMI sensors and SAW transponders is discussed by several measurements. The device shows a relative signal sensitivity of 80 dB/T at low magnetic flux density B<30 mT, quick response (⩾40 MHz bandwidth), and a high-temperature stability View full abstract»

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  • Wavelet-transform-based method of analysis for Lamb-wave ultrasonic NDE signals

    Page(s): 524 - 530
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    A new acoustic nondestructive method using Lamb waves as a probe is presented. These waves are generated and received by an ElectroMagnetic Acoustic Transducer (EMAT). The position of flaws in the structure under test is computed from the time of arrival of the main peak of the reflected signal. Due to the noisy nature of the received signal, we use a wavelet transform algorithm to extract the required time information. The main advantage of such a multi-scale method of signal analysis is to be suitable for peak detection problems especially in highly noisy environments. We explain how we proceed to do the feature extraction, and we propose two methods for reconstructing the image of the inspected structure. Results of real-world ultrasonic Lamb waves signal analysis are presented. In addition, to test the noise robustness of the method, the case of synthetic noisy signals is also treated View full abstract»

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  • A comprehensive model for power line interference in biopotential measurements

    Page(s): 535 - 540
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (112 KB)  

    Power line interference is a major problem in high-resolution biopotential measurements. Because interference coupling is mostly capacitive, shielding electrode leads and a high common-mode rejection ratio (CMRR) are quite effective in reducing power-line interference but do not completely eliminate it. We propose a model that includes both interference external to the measuring system and interference coming from its internal power supply. Moreover, the model considers interference directly coupled to the measuring electrodes, because, as opposed to connecting leads, electrodes are not usually shielded. Experimental results confirm that reducing interference coupled through electrodes yields a negligible interference. The proposed model can be applied to other differential measurement systems, particularly those involving electrodes or sensors placed far apart View full abstract»

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  • Model selection via worst-case criterion for nonlinear bounded-error estimation

    Page(s): 653 - 658
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB)  

    In this paper, the problem of model selection for measurement purpose is studied. A new selection procedure in a deterministic framework is proposed. The problem of nonlinear bounded-error estimation is viewed as a set inversion procedure. As each candidate model structure leads to a specific set of admissible values of the measurement vector, the worst-case criterion is used to select the optimal model. The selection procedure is applied to a real measurement problem, grooves dimensioning using remote field eddy current inspection View full abstract»

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  • Test-set embedding based on width compression for mixed-mode BIST

    Page(s): 671 - 678
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    We present a new test generator circuit (TGC) for mixed-mode built-in self-test (BIST) that embeds a precomputed deterministic test set TD in a longer sequence. The design method employs width compression based on the property of d-compatibles. To demonstrate the feasibility of the TGC design methods, we present experimental data for single stuck-at test sets for the ISCAS 85 circuits and full-scan versions of the ISCAS 89 benchmark circuits. We also achieve significant improvement over another recently-proposed mixed-mode TGC design scheme for BIST View full abstract»

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  • Bayesian approach to spectrophotometric analysis of multicomponent substances

    Page(s): 637 - 642
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    The spectrophotometric analysis of a chemical substance is based on the interpretation of the measurement data acquired by means of a spectrophotometer, i.e., on estimation of the concentrations of its components. In this paper, a Bayesian approach to the estimation of those concentrations is proposed. Its effective application requires a considerable amount of statistical a priori information, viz., the probability density functions characterizing the distributions of the concentrations, of the errors in the data, and of the residual components in the analyzed substance whose concentrations are not estimated. The proposed approach is studied using synthetic data generated on the basis of some real-world reference spectra. The results of study are compared with those obtained by means of the currently used method for estimation of concentrations, viz., constrained least-squares curve fitting View full abstract»

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  • Signal processing support for the evaluation of blood toxic oxidation activity

    Page(s): 541 - 545
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    The problem addressed in this paper is related to numerical correction of spectrometric data aimed at enhancing the quality of interpretation of the spectrum of mixed substances. A digital signal processing method is proposed to eliminate an interfering absorption spectrum and evaluate the blood toxic oxidation activity. The effectiveness of the proposed method is demonstrated using synthetic data and real-world data acquired in biophysical laboratory View full abstract»

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  • Automation of a precision temperature calibration laboratory

    Page(s): 596 - 601
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    The objective of the paper is to discuss the automation of a precision calibration laboratory in the view of achieving maximal quality of metrological performance. Besides automation of measurement equipment for ease of operation, communication and data processing, basic emphasis is given to reliability of operation, flexibility, and possibility of achieving minimal uncertainty for given measurement equipment. Several software design guidelines are discussed in the case of automation of a high-precision temperature calibration laboratory View full abstract»

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  • Sensing strategies for a flexible manipulator

    Page(s): 565 - 572
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    In this paper, we investigate the combination schemes using multisensors for Kalman filtering for modal estimation of a flexible manipulator. In addition to observability, the performance indices regarding the global estimation error covariance, the sensitivity to the initial estimate errors, and the robustness to the round-off errors of the relative noise intensity between process and measurements, are utilized to evaluate the quality of the Kalman filters. The aim is to identify well-conditioned multisensor combinations for which Kalman filters can achieve a specified level of design performance. Case studies for the assessment of the multisensor combination schemes are carried out for Kalman filters with various relative noise intensities. The useful guidelines for achieving the well-conditioned combinations of multisensors are presented View full abstract»

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  • Temperature controlled oven for low noise measurement systems [for electromigration characterization]

    Page(s): 546 - 549
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    Low-frequency noise (LFN) measurements are often applied to the characterization of electron devices. When such measurements have to be performed on electronic components maintained at a given temperature, the thermal stability of the oven which is used for this purpose becomes a major concern, because of the high sensitivity of electron devices to temperature fluctuations (TF's). In this paper, we present the realization of a high-stability temperature-controlled oven, purposely designed for the characterization of electromigration in metal interconnections of integrated circuits by means of low-frequency noise measurements. The prototype which has been realized demonstrates that the contribution of the thermal fluctuations of the oven to the background noise of the measurement system is negligible down to frequencies as low as 10 mHz in the entire range of operating temperatures (25-250°C) View full abstract»

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  • Space compression revisited

    Page(s): 690 - 705
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    This paper discusses new space compression techniques for built-in self-testing (BIST) of VLSI circuits based on the use of compact test sets to minimize the storage requirements for the circuit under test (CUT) while maintaining the fault coverage information. The techniques utilize the concepts of Hamming distance and sequence weights along with failure probabilities of errors in the selection of specific gates for merger of pairs of output streams from the CUT. The outputs coming out of the space compressor may eventually be fed into a time compressor to derive the signature for the circuit. The concept is extended to establish generalized mergeability criteria for merging an arbitrary number of output bit streams under conditions of both stochastic independence and dependence of line errors. The proposed techniques guarantee rather simple design with high fault coverage for single stuck-line faults, with low CPU simulation time and acceptable area overhead. Design algorithms are also proposed, and the simplicity and ease of implementation are demonstrated with examples, primarily through extensive simulation runs on ISCAS 85 combinational benchmark circuits with FSIM, ATALANTA, and COMPACTEST. The paper also provides performance comparisons of the designed space compressors with the conventional linear parity tree space compressor View full abstract»

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  • Optimized CdTe sensors for measurement of electric and magnetic fields in the near-field region

    Page(s): 483 - 487
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB)  

    We present novel electric and magnetic field measurement systems utilizing optical technologies, which have been developed, tested, and calibrated in the frequency region up to 2 GHz. They show an advantage over currently available measurement systems in that they are passive, all-dielectric, and EM immune. A detailed analysis of field perturbation by the measuring probes in the near-field region was performed using finite-difference time-domain (FDTD) algorithm for solving Maxwell's equations. Both probes were calibrated using a gigahertz transversal electric and magnetic cell, and the results show a linear response View full abstract»

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  • Signal interpretation for monitoring and diagnosis, a cooling system testbed

    Page(s): 503 - 508
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB)  

    This paper discusses a method for fault detection and isolation (FDI) in continuous dynamic systems. A key aspect of this approach is the coupling of a qualitative diagnosis engine and a monitoring system that computes symbolic feature values through a signal-to-symbol transformation on the continuously sampled measurement data. Signal analysis techniques with a sound statistical basis are employed to generate reliable symbolic data. The methodology is evaluated on the diagnosis of engineered faults in the cooling system of an automobile engine that has been instrumented with temperature and pressure sensors. Results show the interdependency between modeling for diagnosis and the feature extraction system View full abstract»

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  • Multifactorial movement analysis in weightlessness: a ground-based feasibility study

    Page(s): 476 - 482
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    This paper discusses the activities conducted within the framework of the design and implementation of the Microgravity Investigation and Crew Reactions in 0-Gravity (MICR0-G) facility for quantitative multifactorial human motion analysis on board the International Space Station. In particular, we report the preliminary feasibility evaluation of the combined use of existing space hardware for reaction dynamic measurements (EDLS) and video-based systems for kinematics analysis. The experiments were performed at the Man-Vehicle Laboratory (MVL) of the Massachusetts Institute of Technology (MIT), Cambridge, with the main goal of validating the EDLS system as a conventional ground reaction measurement device. The results demonstrate the suitability of the dynamic measurement system as a space-qualified force platform and form a set of methodological requirements for design and combined use of the two systems. Considerations on the reliability of inverse dynamics models, when applied to microgravity kinematics data, confirm the necessity to rely on multifactorial joint systems for movement and posture investigation in weightlessness View full abstract»

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  • Elimination of shunting conductance effects in a low-cost capacitive-sensor interface

    Page(s): 531 - 534
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (72 KB)  

    A low-cost and reliable interface for capacitive sensors, based on the use of a relaxation oscillator and a microcontroller, is presented. The novel interface system is designed to measure small capacitances in a reliable and accurate way even when the sensor capacitors are shunted by parasitic conductances. The problem of shunting conductances is solved by performing a series of eight measurements and using a new auto-calibration technique. Moreover, all multiplicative and additive errors of the interface are also eliminated by using this new auto-calibration technique. In the microcontroller, the final result is calculated based on the new measurement algorithm. A prototype has been built and tested. Experimental results show that the interface is able to measure a capacitance of 0-1.2 pF with a shunting conductance of up to 0.42 μS, with a resolution and a relative accuracy of 0.03% and ±0.15%, respectively. The measurement time is about 400 ms View full abstract»

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  • Nonlinear distortions and multisine signals. I. Measuring the best linear approximation

    Page(s): 602 - 609
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    This paper examines the effects of nonlinearities on frequency response function measurements using periodic multifrequency signals. A class of broadband pilot test signals is proposed, termed sparse odd multisines, which can be used to establish the system bandwidth and detect nonlinearities. Signals are then defined within this class which allow the measurement of the best linear approximation of a nonlinear system. A comparison is made with related work in this area View full abstract»

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  • Small sinusoidal vibrations amplitude measurements with the Michelson interferometer

    Page(s): 643 - 647
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    Traditionally, small amplitude vibrations are measured with the Michelson interferometer in discrete amplitude values. This paper extends this measuring method to amplitudes lying in continuous intervals. The theory was checked by studying the vibrations of a quartz crystal. The analysis of the experimental results leads to the conclusion that this method can be used for vibration measurements with nm amplitude View full abstract»

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  • Using cereal grain permittivity for sensing moisture content

    Page(s): 470 - 475
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    A brief history of cereal grain moisture measurement by sensing the electrical properties of grain is presented. The basic principles are also described for using radio-frequency (RF) and microwave dielectric properties, or permittivity, of grain for sensing moisture through their correlation with moisture content. The development of density-independent functions of the permittivity is explained. The findings of recent research are summarized, which indicate that reliable density-independent moisture content determinations can be realized by measurements on grain at RF and microwave frequencies. Development of these techniques will provide useful instruments for on-line monitoring of moisture content in flowing grain to manage moisture in grain, prevent spoilage in storage and transport, improve processing, and provide information important for yield determinations in precision agriculture applications View full abstract»

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  • Combined detection of respiratory and cardiac rhythm disorders by high-resolution differential cuff pressure measurement

    Page(s): 498 - 502
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    The aim of this paper is to present a new, noninvasive method to detect respiratory and cardiac rhythm disorders. We measure pressure variations within a lightly inflated cuff wrapped around the wrist, related to changes in the blood arterial pressure. By suitable numerical processing, it is possible to extract from this signal the information on respiratory and cardiac rhythms, as well as to detect and differentiate a number of sleep disorders such as central and obstructive apneas. The main ideas are presented through exemplary results with comments View full abstract»

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  • Robust and accurate real-time estimation of sensors signal parameters by a DSP approach

    Page(s): 685 - 689
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (76 KB)  

    The paper presents a spectral method for robust and accurate real-time frequency estimation when a square wave affected by impulsive noise is considered. The method, tailored for signals coming from typical resonant sensors (frequency from 2 kHz to 22 kHz), has been implemented and tested using a floating-point digital signal processor (DSP) and a 16-bit analog-to-digital converter (ADC). It has been observed that there is a greater immunity to glitches with respect to the classic solution based on Constant Elapsed Time, while resolution (10-6) and measuring time (10 ms), are close to the ones of traditional high-cost laboratory instrumentation View full abstract»

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  • Oscillator-based interface for measurand-plus-temperature readout from resistive bridge sensors

    Page(s): 585 - 590
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    A signal conditioning circuit based on a relaxation oscillator is proposed for use with resistive bridge sensors. The circuit provides a rectangular-wave output whose frequency is related to the bridge unbalance, and duty-cycle is a function of the overall sensor bridge resistance, hence of the sensor operating temperature. In this way, two measurement values are simultaneously and independently carried on the same output signal. The circuit makes use of a constant current bridge excitation which enables the connection of remote sensors without accuracy degradation, and moreover, for silicon piezoresistive sensors, provides a first-order temperature compensation. A frequency-doubling output stage significantly reduces the nonlinearity due to switching delay times, at the parity of output center frequency and span. Experimental results are reported on the characterization of both the circuit alone and interfaced to a silicon pressure sensor View full abstract»

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  • Magnetoresistive power sensor for measurement in situ of RF power absorbed by tissue

    Page(s): 513 - 516
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    A new magnetoresistive sensor for use in medical RF heating and hyperthermia is presented. This sensor has dc output proportional to RF power absorbed in tissue. The operating principle of the sensor consists of multiplication of the instantaneous value of the RF current and voltage in a microstrip transmission line using a magnetoresistive element. At an operating frequency of 915 MHz in a 20% bandwidth, it has a sensitivity of 22 μV/W, insertion losses less than 0.1 dB and nonlinearity less than 3% up to 300 W. The uncertainty caused by the reflected waves with arbitrary phase is less than 3.5% up to the voltage standing wave ratio (VSWR) equals 3 View full abstract»

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  • Detection of methacholine with time series models of lung sounds

    Page(s): 517 - 523
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (196 KB)  

    A new method for the extraction of features from stationary stochastic processes has been applied to a medical detection problem. It illustrates a practical application of automatic time series modeling. Firstly, the model type and the model order for two time series prototype models are selected. The prototypes represent the lung noises of a single healthy subject, before and after the application of methacholine, using the model error ME as a measure for the difference between time series models, new data can be divided into classes that belong to the prototype models for this person. The prototype models are obtained from a few expiration cycles under known conditions. This is sufficient to detect the presence of methacholine in new data of the same subject if he is able to maintain stationary conditions by following accurately the prescribed breathing pattern. It is not necessary to use the same model type and the same model order for the prototypes and for new data. Automatically and individually selected models for prototypes and data give a good detection of methacholine View full abstract»

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  • Nonlinear distortions and multisine signals. II. Minimizing the distortion

    Page(s): 610 - 616
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (104 KB)  

    For Pt. I see ibid. vol. 49, pp. 602-609, 2000. This paper examines the effects of nonlinear distortions on frequency response functions estimated using multisine test signals. The aim is to minimize the distortion introduced by the nonlinearity, for a given input power constraint. A number of different multisine signals are compared for this purpose, with zero, random and low crest factor harmonic phases. The results are compared with those of other authors in this field View full abstract»

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  • Pressure measurement of air cushions for SCI patients

    Page(s): 666 - 670
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    Pressure sores are a serious problem for spinal cord injury (SCI) patients. Many kinds of pressure-relieving cushions have been developed to distribute the patient's weight evenly and widely. In rehabilitation medicine, the selection and the adjustment of the wheelchair cushion must be done very carefully by the medical staff to prevent pressure sores. We measured the buttock pressure distribution of SCI patients using the Tekscan pressure measurement system. In this paper, we calculate six parameters and represent these parameters on a hexagonal radar plot to evaluate the pressure distribution of wheelchair cushions. We believe this radar plot can be very useful for medical personnel when selecting and adjusting wheelchair cushions and adjusting the posture of SCI patients View full abstract»

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Aims & Scope

Papers are sought that address innovative solutions to the development and use of electrical and electronic instruments and equipment to measure, monitor and/or record physical phenomena for the purpose of advancing measurement science, methods, functionality and applications.

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Editor-in-Chief
Prof. Alessandro Ferrero
Dipartimento di Elettrotecnica
Piazza Leonardo da Vinci 32
Politecnico di Milano
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alessandro.ferrero@polimi.it
Phone: 39-02-2399-3751
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