IEEE Transactions on Instrumentation and Measurement

Volume 39 Issue 4 • Aug 1990

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Displaying Results 1 - 25 of 27
  • A variable frequency method for wide-band microwave material characterization

    Publication Year: 1990, Page(s):609 - 614
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    A variable reactance termination method for measurement of the complex permittivity spectra is described. The method uses modern frequency swept sources and is semi-automated. The frequency variable replaces mechanical tuning for improved measurements and optimization of sensitivity. Sources of errors are outlined, and range and limitations on conductivity are discussed. Results of measurements of... View full abstract»

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  • A bell-shape pulse generator

    Publication Year: 1990, Page(s):667 - 670
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    A simple circuit for forming the function Y=exp(-X2 /2) is described. The original curve is approximated with three quadratic parabolas using the method of least-squares estimation. The approximation function is generated through analog integration of a linear voltage with appropriate shape View full abstract»

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  • A digital method for the determination of the magnetic characteristic of variable reluctance motors

    Publication Year: 1990, Page(s):604 - 608
    Cited by:  Papers (34)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    A digital method is proposed for the measurement of the magnetic flux, starting from the digital integration of the induced electromotive force (EMF). The method features sensitivity and accuracy greater than, or at least as high as, that of other methods, and is applied to the determination of the flux-linkage-versus-current diagrams of a variable-reluctance (VR) motor. Two different methods are ... View full abstract»

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  • A high resolution digital frequency meter for low frequencies

    Publication Year: 1990
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (92 KB)

    A digital frequency meter using frequency multiplication is described. It can be used in utility power system control centers and other low-frequency applications where resolutions of the order of 1/100 Hz and almost instantaneous readouts are essential. Possible improvements of the circuit are suggested View full abstract»

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  • A 300-A delta VF tester

    Publication Year: 1990, Page(s):599 - 603
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    The design and development of a relatively low-cost, high-current, transient thermal resistance tester are described. The tester, which employs delta techniques, was initially used to measure the die bond integrity of large power handling rectifier assemblies, but because of its versatility it can thermally characterize most semiconductor junctions. Circuit design details and testing of several pr... View full abstract»

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  • Velocity sense detection based on the spatial filter method

    Publication Year: 1990, Page(s):649 - 652
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    A technique for determining the velocity sense using a pair of parallel spatial filters arranged in opposing senses (or using a single differential spatial filter) is proposed. This method is analogous to the relationship between convolutions and correlations. By mapping the relationship into the spatial domain, where the motion occurs, and applying simple signal-processing procedures to the pair ... View full abstract»

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  • A digital frequency independent phase meter

    Publication Year: 1990, Page(s):665 - 667
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    A digital, frequency-independent phase meter is described. It makes use of pulses derived from the multiplication of the frequency of the reference input signal as its clock pulses instead of conventional crystal controlled clock generators. Advantages of the meter include simplicity and the elimination of gating error. The main source of error for this circuit is harmonic distortion of the input ... View full abstract»

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  • A circuit for constant phase shift using a narrow pulse duty cycle all-pass filter

    Publication Year: 1990, Page(s):594 - 598
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    A technique for providing constant phase shift irrespective of frequency for sinusoidal signals is presented. The system contains a loop with a narrow pulse duty cycle all-pass switching filter whose phase shift is regulated by the switching frequency. By using narrower switching pulses and a higher switching frequency, the quality of the sine wave output and the phase accuracy is improved. Experi... View full abstract»

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  • Ellipsometry measurements on refractive index profiles of thin films

    Publication Year: 1990, Page(s):642 - 648
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (556 KB)

    An ellipsometry technique for measuring the arbitrary refractive index profile of composite thin films is presented. The refractive index profile is obtained through a successive partitioning and computation process on measured data points with the aid of a φ0/T plot, which reduces errors. Analyses of the required number of data points in the partitioned sections, the error... View full abstract»

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  • An iterative two-phase procedure for automatic optimization of positioning servo parameters

    Publication Year: 1990, Page(s):673 - 676
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    An automatic time-domain tuning procedure is introduced and applied to the tuning of a PID positioning controller of a simulated elevator system. The procedure contains two optimization phases: optimization of the leveling accuracy and optimization of the acceleration characteristics. The results show that the procedure is suitable for applications where accurate leveling is not the only requireme... View full abstract»

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  • A novel high common mode DC ammeter

    Publication Year: 1990, Page(s):664 - 665
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    A wide-range DC ammeter for laboratory research, capable of operating at high voltage, is described. Low cost, easy construction, versatility, and commonly available components were desired design requirements. The ammeter consists of a series-connected microammeter and milliammeter. Specifications include linear current sensing from 1 μA to 1 mA with a fixed linear scale resolution of 1 μA/... View full abstract»

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  • Instrumentation amplifier with digital gain programming and common-mode rejection trim

    Publication Year: 1990, Page(s):588 - 593
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    A design for an instrumentation amplifier with digitally programmable gain and common-mode rejection (CMR) trim is presented. A standard multiplying D/A converter (DAC) is used as the differential feedback control element, and the common-mode rejection is provided by four resistors in a configuration equivalent to a balanced bridge. Digital CMR adjustment is established after another bridge-balanc... View full abstract»

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  • A globally periodic signal analysis

    Publication Year: 1990, Page(s):574 - 577
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    A method is presented for analyzing a square-wave signal, which is not treatable by the usual methods of analysis because of perturbations affecting its periodicity. The method is based on the Fourier series concept. This makes it possible to compute and link the Fourier coefficients to the Fourier transform of the distribution of the random variable τ View full abstract»

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  • An Allan variance real-time processing system for frequency stability measurements of semiconductor lasers

    Publication Year: 1990, Page(s):637 - 641
    Cited by:  Papers (8)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB)

    A real-time frequency stability measurement system for semiconductor lasers was developed. Since the frequency of the input signal is measured successively without clearing the counter, measurements of the Allan variance made with this system are more accurate than those made with conventional instruments. The Allan variance can be measured for integration times τ from 1 μs to 10000 s, and ... View full abstract»

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  • Increased time-constant dual-input integrators

    Publication Year: 1990, Page(s):672 - 673
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB)

    Two active-RC integrators are proposed. They provide ideal integration function realization with dual-input capability, the use of a grounded capacitor, and an increase in time-constant ( tau 0) over its nominal value ( tau ), which is made possible by a single resistor-controlled multiplier. Sensitivity characteristics of the proposed networks are considered. The integrators have been ... View full abstract»

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  • A low cost high resolution optical position sensor

    Publication Year: 1990, Page(s):658 - 663
    Cited by:  Papers (16)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (548 KB)

    A fast high-resolution analog position sensor that provides real-time analog output corresponding to the position of the centroid of a diffuse optical source focused on its surface, is described. Theoretical performance equations are presented. Linear and two-dimensional position sensors have been fabricated and tested to verify the basic theory. Analytic results for system static transfer functio... View full abstract»

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  • Measurement of apparent power components in the frequency domain

    Publication Year: 1990, Page(s):583 - 587
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    An algorithm and a digital signal-processing technique are proposed for the measurement of the apparent power components in the frequency-domain approach. The discrete Fourier transform (DFT) is applied to simultaneous samples of voltage and current waveforms to compare their respective spectra. The RMS values of the harmonic currents flowing between the source and the load (resistive, reactive, a... View full abstract»

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  • Robust identification of transfer functions in the s- and z-domains

    Publication Year: 1990, Page(s):565 - 573
    Cited by:  Papers (62)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (652 KB)

    A frequency-domain maximum-likelihood estimator (MLE) for estimating the transfer function of linear continuous-time systems developed by J. Schoukens et al. (1988) assumes independent Gaussian noise on both the input and the output coefficients. A Gaussian frequency-domain MLE for transfer functions of linear continuous or discrete time invariant systems in an errors-in-variables model is present... View full abstract»

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  • Position, velocity profile measurement of a moving body by microwave interferometry

    Publication Year: 1990, Page(s):632 - 636
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    A telemetric sensor that uses microwave interferometry to determine the velocity profile of a moving body following a known linear trajectory is proposed. By a slight modification of the design, it is possible to determine both the velocity profile and the distance to the trajectory. The principle of the method and the preliminary experiments carried out in the laboratory before extending the proc... View full abstract»

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  • Global iterative solution of dielectric spectroscopy equations

    Publication Year: 1990, Page(s):615 - 620
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    A global method is presented for solving the permittivity equations for open- and short-circuited coaxial lines of general length for broadband measurements by iterating the recurrence schemes zn+1=c cot zz and z n+1=c tan zn, respectively, and their inverses. The global iteration theory of Fatou and ... View full abstract»

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  • Novel pseudo RMS current converter for sinusoidal signals using a CMOS precision current rectifier

    Publication Year: 1990, Page(s):670 - 671
    Cited by:  Papers (43)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    A very simple pseudo RMS-to-DC current converter for sinusoidal signals is described. The most salient feature of the circuit is that it uses a CMOS precision current rectifier consisting of only two transistors and thus operates throughout in the current domain. The full-wave rectifier was built using CD4007 devices and tested. It was observed that the transfer curve is sharp even at low nanoampe... View full abstract»

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  • Array of sensors with A/D conversion based on flip-flops

    Publication Year: 1990, Page(s):653 - 657
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    An array of silicon light intensity sensors is described. Switched bias flip-flops are used to obtain a digital output. The flip-flops contain bipolar transistors which are sensitive to illumination. A triangle-wave voltage is used for analog-to-digital conversion. An analysis of the resolution of the measurement technique when it is used for low-signal level high-resolution measurement is present... View full abstract»

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  • A temperature difference-to-frequency converter using resistance temperature detectors

    Publication Year: 1990, Page(s):676 - 677
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (172 KB)

    A novel temperature difference-to-frequency (TD/F) converter using two platinum resistance temperature detectors (RTDs) has been developed. The resistance difference of two RTDs is converted into a DC current to control the simulated inductor, which is designed so that its inductance is inversely proportional to the square of the current. The simulated inductor forms the resonant circuit of a Colp... View full abstract»

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  • Dual networks and self-checking dividers

    Publication Year: 1990, Page(s):578 - 582
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    Methods of establishing dual network pairs and self-checking dividers from a string of 12 nominally equal resistors permanently connected in series using short-circuiting links between nodes are described. Dual networks that can be generated from a string of 11 nominally equal resistors, permanently connected in series with Hamon star junctions by joining one or more nodes together with one or mor... View full abstract»

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  • Neural network signal understanding for instrumentation

    Publication Year: 1990, Page(s):558 - 564
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    A report is presented on the use of neural signal interpretation theory and techniques for the purpose of classifying the shapes of a set of instrumentation signals, in order to calibrate devices, diagnose anomalies, generate tuning/settings, and interpret the measurement results. Neural signal understanding research is surveyed, and the selected implementation and its performance in terms of corr... 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.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief

SHERVIN SHIRMOHAMMADI
School of EECS
University of Ottawa
800 King Edward Ave.
Ottawa, Ontario
K1N 6N5 CANADA
Fax: 613-562-5664
shervin@discover.uottawa.ca