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Instrumentation and Measurement, IEEE Transactions on

Issue 4 • Date Aug. 1997

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Displaying Results 1 - 25 of 61
  • Evaluation of a voltage source with three calculable RMS outputs

    Page(s): 784 - 788
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (99 KB)  

    This paper describes a voltage source which generates three different waveforms. Measurement techniques with such a source are proposed, with emphasis on the uncertainty of each waveform used, when the ac amplitude is defined with a dc calibration of the source. The instrument circuitry and operation is described. Measurement results are also discussed. Emphasis is given to selected parameters of waveforms and to their effect on the measured rms value. View full abstract»

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  • Sinewave fit algorithm based on total least-squares method with application to ADC effective bits measurement

    Page(s): 1026 - 1030
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB)  

    Sinewave fit is a fundamental task in many test and measurement systems. The characterizations of analog-digital converters and digital oscilloscopes are two examples. In this paper, we present a high-performance (i.e., high-precision and high-speed) algorithm to estimate the four parameters of a sinewave from a sample data record. By the use of trigonometric identity, we propose a frequency estimator that turns the nonlinear estimation problem into a linear one. Thus, the difficulty of the traditional nonlinear least-squares sinewave fit method is attenuated. The total least-squares method is used to estimate four parameters of a sinewave in order to minimize the estimation errors in the sense of l2 norm. Simulation results exhibit that the proposed method gives superior performance over traditional ones and achieves excellent estimation of the true resolution of the simulated ideal ADC. This new algorithm is noniterative and gives swift and consistent results View full abstract»

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  • Common error sources in using a series-resistors-type voltage divider below the level of 0.01 ppm

    Page(s): 776 - 780
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    A series-resistors-type voltage divider is one of the most commonly used dividers. We have carefully analyzed various error sources such as leakage current, normal mode rejection ratio of the voltmeter, temperature coefficient, and others. The KRISS' 10:1 divider which was used for 10-V calibration was chosen for this study. Here, we would like to describe some common error sources and their effects which should be taken into account in the level of 10-8 or below for the series-resistors type voltage dividers View full abstract»

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  • Two new six-port reflectometers covering very large bandwidths

    Page(s): 966 - 969
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (100 KB)  

    This paper presents two new structures for six-port reflectometers with very large operating bandwidths of more than three decades, using a combination of lumped reflectors and transmission lines. Circuits working over a range of 2 MHz to 1300 MHz and 2 MHz to 2200 MHz have been built using inexpensive passive surface mount elements and Schottky detector diodes. Comparing results obtained from the new proposed structures with those obtained from a commercial network analyzer showed a worst case absolute value of 0.020 for the complex difference between the measured reflection coefficients. A convenient calibration procedure, for the entire band, is proposed using three standards and four approximately known loads View full abstract»

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  • A wideband sampling voltmeter

    Page(s): 947 - 953
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    A high-accuracy sampling voltmeter, designed to span the frequency range of 10 Hz-200 MHz, is described. The instrument operates autonomously, at a measurement update rate of at least one per second. A novel quasiequivalent time sampling process is used, with a custom strobed comparator as the sampling device and decision element. The architecture and control are presented, along with the time-base design principles. Major error sources associated with the time-base are also discussed View full abstract»

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  • Spectral analysis methods for Poisson sampled measurements

    Page(s): 882 - 887
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (160 KB)  

    The velocity measurements for turbulent flow regimes obtained with laser Doppler anemometry are not only affected by random noise but are also unevenly spaced in time. The usual spectral estimators rely on evenly spaced data points. It would appear then that the measurement data requires adjustment before it can be passed on to these estimators. In this paper, both an analysis method with a novel adjustment scheme as well as an analysis method which does not rely on the use of adjustment schemes, are presented View full abstract»

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  • Techniques of improved signal extraction in scan conversion-based transient digitizers

    Page(s): 893 - 898
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB)  

    This paper deals with a technique to improve the signal extraction from the target diode matrix of scan conversion-based transient digitizers. The target charge distribution corresponding to the input signal is analyzed through statistical-based techniques. The identification of the distribution model allows main distortion effects to be identified and corrected. Experimental results of tests carried out on an actual scan converter using dc and sine wave signals showed that signal extraction can be improved mostly by correcting the center displacement of the column distributions View full abstract»

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  • Optimized sinewave test of waveform digitizers by a DFT approach

    Page(s): 970 - 974
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (140 KB)  

    This paper presents a particularly simple and effective discrete Fourier transform (DFT)-based approach for digitizing waveform recorder testing. Its implementation is straightforward and signal processing requirements are confined to the calculation of the DFT, which can be carried out by a readily implemented fast Fourier transform algorithm. Adjustments to the test generator can be determined to ensure that tests are carried out under optimal conditions, providing accurate and reliable estimates of digitizer performance parameters View full abstract»

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  • Time domain analysis and its practical application to the measurement of phase noise and jitter

    Page(s): 1016 - 1019
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    The precise determination of phase is necessary for a very large set of measurements. Traditionally, phase measurements have been made using analog phase detectors which suffer from limited accuracy and dynamic range. This paper describes how phase digitizing, which uses time domain techniques, removes these limitations. Phase digitizing is accomplished using a time interval analyzer, which measures the signal zero-crossing times. These zero-crossing times are processed to compute phase deviation, with the reference frequency specified as a numerical value or derived from the times themselves. Phase digitizing can be applied even in the presence of modulation, as the underlying clock can be reconstructed in software to fit the data. Measurements derived from this phase data such as phase noise, jitter analysis, Allan variance (AVAR), maximum time interval error (MTIE), and time deviation (TDEV) are applied to such applications as the characterization of oscillators, computer clocks, chirp radar, token ring networks, and tributaries in communication systems View full abstract»

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  • Artificial neural networks in estimation of hydrocyclone parameter d50c with unusual input variables

    Page(s): 908 - 912
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (84 KB)  

    The accuracy in the estimation of hydrocyclone parameter, d50c, can substantially be improved by application of artificial neural networks (ANN). With ANN, many nonconventional operational variables such as water and solid split ratios, overflow and underflow densities, apex and spigot flowrates can easily be incorporated as the input parameters in the prediction of d50c. The ANN yields high correlation of data, hence it can be used in automatic control and multiphase operations of hydrocyclones View full abstract»

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  • Light-to-frequency converter using integrating mode photodiodes

    Page(s): 933 - 936
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (104 KB)  

    An optical sensor for operation in the visible spectrum with integrated electronic readout circuits has been realized in a BIFET process. The output signal is a pulse series with a frequency proportional to the intensity of the incident light. Furthermore, the duty-cycle of the output pulses depends on the spectral distribution of the incident light, enabling the measurement of color. The electronic circuits have been designed for operating with a large dynamic range, while using only a relatively small chip area. No internal or external capacitor is needed for the current-to-frequency conversion, since the photodiode operates in the charge integrating mode. This enables fabrication of arrays of smart image detectors where a large area can be used for the photodetector View full abstract»

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  • A new sensor for paper basis-weight and ash-content measurements

    Page(s): 937 - 940
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (112 KB)  

    In this paper, a new decoupling measure approach, which can avoid the shortcomings of the paper sheet basis-weight and ash-content sensors available now, is proposed. A new type of sensor is designed and produced. A test has been performed, and the experimental results show that the new type sensor gives excellent performance View full abstract»

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  • Integrated time-of-flight laser radar

    Page(s): 996 - 999
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (76 KB)  

    A small, hand-held pulsed time-of-flight (TOF) laser radar device has been designed and tested. The aim was to implement the receiver channel and time-to-digital converter (TDC) with application-specific integrated circuits (ASIC's) in order to reduce power consumption, cost, weight, and size. The measurement range of the device is from 1 m to 30 m to a noncooperative target, and an accuracy of 35 mm is achieved with a measuring time of 200 ms between temperatures of -10°C and +30°C. Power consumption during continuous measurement is 0.84 W View full abstract»

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  • Complex electron wave reconstruction using parameter estimation

    Page(s): 826 - 830
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB)  

    A new method is proposed for the reconstruction of the complex valued exit wave of a periodic specimen in a transmission electron microscope. The method uses a series of images recorded at different defoci. From these, inherently noisy, images the parameters defining the wave are estimated. The method keeps the number of parameters as small as possible. In addition, in simulations, it has been found to always produce the exit wave estimate fitting best to the images recorded View full abstract»

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  • A fiber optic sensor for the measurement of surface roughness and displacement using artificial neural networks

    Page(s): 899 - 902
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    This paper presents a fiber optic sensor system, artificial neural networks (fast back-propagation) are employed for the data processing. The use of the neural networks makes it possible for the sensor to be used both for surface roughness and displacement measurement at the same time. The results indicate 100% correct surface classification for ten different surfaces (different materials, different manufacturing methods, and different surface roughnesses) and displacement errors less then ±5 μm. The actual accuracy was restricted by the calibration machine. A measuring range of ±0.8 mm for the displacement measurement was achieved View full abstract»

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  • Test of subranging A/D converters with digital correction

    Page(s): 975 - 979
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (132 KB)  

    A test methodology based on linear modeling of subranging analog-to-digital converters with digital correction is proposed. A reduced physical model of integral nonlinearity errors is obtained by the application of the ambiguity algorithm. Simulation results are provided which demonstrate that an appreciable reduction of the number of test points can be obtained, thus reducing the high costs of testing, with low prediction errors View full abstract»

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  • Wirelessly interrogable surface acoustic wave sensors for vehicular applications

    Page(s): 1031 - 1038
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB)  

    Wirelessly interrogated passive surface acoustic wave (SAW) sensors for measurements in a rough environment are shown. These can be applied when remote readout is necessary and other sensors cannot withstand heat, dirt, mechanical vibration, and/or electromagnetic interference. Applications of passive SAW sensors for sensing tasks, especially in vehicles are discussed. The implementation of SAW sensors for measurements of torque and speed of revolution on transmission shafts is discussed. We present measurements of railway disc brake temperature by on-disc SAW sensors and wireless measurement of the air pressure in the tires of road vehicles in motion. The applied SAW sensors, the corresponding interrogation systems and an algorithm for signal processing are described. Estimations of measurement errors and results of measurements are discussed View full abstract»

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  • Single-chip interpolating time counter with 200-ps resolution and 43-s range

    Page(s): 851 - 856
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    In this paper, we present a design and test results of the interpolating time counter implemented on a single field programmable gate array (FPGA) chip. The counter contains two 6-bit time-to-digital converters (TDCs), each having 200-ps resolution (LSB) within 10 ns range, and the 32-bit, 100-MHz real-time counter, which is also used for frequency measurement. The utilization of the logic cells on the FPGA chip is 93%. The software correction of the TDC's nonlinearity errors resulted in lowering the random error of the counter to 0.65 LSB or 129 ps (RMS) View full abstract»

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  • A method to evaluate cracks in a superconductive cylinder used to shield weak magnetic fields

    Page(s): 873 - 876
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (100 KB)  

    To survey the local superconductivity and cracks in a large superconductor, a method for estimating the property from the difference in the real component ΔR and imaginary component ΔX of the complex impedance of a coil with a sample and another without one is proposed. This method was applied to two samples one which was superconductive and one not superconductive at 77.3 K. It is understood that samples become superconductive when ΔR is sufficiently near 0 and ΔX is negative. The relation between two superconductors, one without and the other with artificially induced cracks was experimentally investigated. It was confirmed that the property of the sample with cracks deviated from superconductivity. As for a superconductive cylinder of 0.5 m in diameter and 1 m in length open at one end, ΔR and ΔX at various points on the wall and at the closed end were measured at 77.3 K and the values of ΔR were sufficiently near 0. All values of ΔX were negative. The magnetic shielding effect was confirmed to be 1/20000 View full abstract»

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  • A cubic FIR-type filter for numerical correction of spectrometric data

    Page(s): 922 - 928
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (236 KB)  

    The raw results of spectrometric analysis are subject to systematic errors of an instrumental type that may be reduced provided a mathematical model of the instrumental imperfections or its pseudoinverse, i.e., an operator of reconstruction, is identified. The idea to identify the operator of reconstruction, having the form of a cubic FIR-type filter, directly during calibration is developed in this paper. A corresponding algorithm is proposed and studied using spectrometric-type synthetic and real-world spectrophotometric data. The results are compared with those obtained by means of the algorithms, often used for spectrometric data correction View full abstract»

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  • Parametric optimization of measuring systems according to the joint error criterion

    Page(s): 769 - 775
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    This paper presents a method and exemplary results of the modeling and design of measuring systems. The minimum of designed system errors is achieved using parametric optimization methods of a measuring system model. A “structural method” of measuring system modeling is used. The properties of the equipment used, as well as data processing algorithms, are taken into account View full abstract»

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  • Determination of nonlinear delay elements within NARMA models using dispersion functions

    Page(s): 868 - 872
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (220 KB)  

    In nonlinear system identification of discrete-time models, it is critical to determine the nonlinear delay elements within models. This paper proposed the use of dispersion functions to pre-determine the significant delay elements which appear in nonlinear form within an unknown nonlinear autoregressive, moving-average (NARMA) model. The methodology is based on orthogonal projection, the use of dispersion functions, and hence meets the criterion of mean-squared error. According to the properties of dispersion functions, rules can be made to determine the possible delay elements by giving the observed input and output data. Furthermore, the rules of the determination are independent of the degree-of-nonlinearity of the model. Finally, computer simulations were performed and showed coinciding results View full abstract»

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  • Ultralow-noise PC-Based measurement system for the characterization of the metallizations of integrated circuits

    Page(s): 789 - 793
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (92 KB)  

    The design, realization, and test of a multichannel ultralow-noise data acquisition system are described in this paper. The instrument, controlled by a personal computer (PC), has been specifically designed for performing low-frequency noise measurements on interconnect lines of an integrated circuits. A specifically designed ultralow-noise preamplifier has been realized and an optical link has been used for connecting the front-end of the instrument with the PC in order to minimize the effects of electromagnetic interferences. An overall background noise some orders of magnitude below that of preexisting instrumentation has been obtained. In particular, the power spectral density of the equivalent input voltage noise was 1.5, 3, 10 nV/(Hz)1/2 at 1, 0.1, and 0.01 Hz, respectively View full abstract»

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  • Real-time determination of power system frequency

    Page(s): 877 - 881
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    The main frequency is an important parameter of an electrical power system. The frequency can change over a small range due to generation-load mismatches. Some power system protection and control applications, e,g, frequency relay for load shedding, load-frequency controller, require accurate and fast estimation of the frequency. Most digital algorithms for measuring frequency have acceptable accuracy if voltage waveforms are not distorted. However, due to nonlinear devices, e,g, semiconductor rectifiers, electric arc furnaces, the voltage waveforms can include higher harmonics. The paper presents a new method of measurement of power system frequency, based on digital filtering and Prony's estimation method. Simulation results confirm, that the proposed method is more accurate than others, e,g, than the method based on the measurement of angular velocity of the rotating voltage phasor View full abstract»

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  • Measuring RF and microwave permittivities of adult rice weevils

    Page(s): 941 - 946
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB)  

    The dielectric permittivities of bulk samples of adult rice weevils were measured over the frequency range from 0.2 GHz to 20 GHz at temperatures from 10°C to 65°C with an open-ended coaxial-line probe, network analyzer, and a sample temperature control assembly designed for the measurements. Repeated measurements were highly variable, because mean sample bulk densities did not accurately reflect effective densities of the bulk rice weevil samples in the small volume of sample sensed by the coaxial-line probe. Density corrections based on earlier permittivity measurements on bulk rice weevil samples at 9.4 GHz, at known sample densities, removed much of the variability. The corrections utilized the linear relationship between the cube root of the dielectric constant and bulk density, which permitted estimates of the weevil body permittivities to be obtained with the Landau, Lifshitz, and Looyenga equation for dielectric mixtures. Estimated dielectric constants and loss factors of the insects from averages of seven different measurement sequences are presented graphically for temperatures from 15°C to 65°C 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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Meet Our Editors

Editor-in-Chief
Prof. Alessandro Ferrero
Dipartimento di Elettrotecnica
Piazza Leonardo da Vinci 32
Politecnico di Milano
Milano 20133 Italy
alessandro.ferrero@polimi.it
Phone: 39-02-2399-3751
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