The authors present results on the effect of moisture obtained by computer-aided measurements of the quality factor and the resonant frequency of a microwave cavity containing three to sixteen grains of the test product. Simultaneous measurements of moisture, temperature, dielectric constant, dielectric losses, and absorbed power were performed on agricultural products (e.g., rice, sarrasin, wheat, barley) and some porous granular ceramic products (molecular sieves or zeolites). The test grains were suspended from a gravimetric balance and were dried over a short period of time inside the test cavity by microwave power. The bone dry weight of the samples used to calculate the moisture level is accurately determined in these measurements: a sudden change occurs in the dielectric loss of the test sample when the grains begin to char. In the case of granular ceramic products (zeolites), more stable results are obtained.<>
{"title":"The precise measurement of the permittivity and moisture content of granular products","authors":"C. Akyel, R. Bosisio","doi":"10.1109/IMTC.1989.36920","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36920","url":null,"abstract":"The authors present results on the effect of moisture obtained by computer-aided measurements of the quality factor and the resonant frequency of a microwave cavity containing three to sixteen grains of the test product. Simultaneous measurements of moisture, temperature, dielectric constant, dielectric losses, and absorbed power were performed on agricultural products (e.g., rice, sarrasin, wheat, barley) and some porous granular ceramic products (molecular sieves or zeolites). The test grains were suspended from a gravimetric balance and were dried over a short period of time inside the test cavity by microwave power. The bone dry weight of the samples used to calculate the moisture level is accurately determined in these measurements: a sudden change occurs in the dielectric loss of the test sample when the grains begin to char. In the case of granular ceramic products (zeolites), more stable results are obtained.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129824479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The author describes a 1-megasamples/s 16-bit analog-to-digital converter (ADC) that uses a subranging conversion technique. High accuracy at a 1-MHz conversion rate is obtained with novel circuits developed for a track-and-hold device, a residue amplifier, and a digital-to-analog converter. Design aspects of these key functional circuits are presented. A prototype ADC was fabricated on a printed-circuit board and tested. Curve-fit test results show that up to 100 kHz, the effective bits decrease to 14 bits due to wideband noise. However, signal bandwidth is commonly restricted in spectrum analysis, so a dynamic range of over 96 dB can be obtained.<>
{"title":"A 1 Ms/s 16-bit analog-to-digital converter","authors":"M. Imamura","doi":"10.1109/IMTC.1989.36810","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36810","url":null,"abstract":"The author describes a 1-megasamples/s 16-bit analog-to-digital converter (ADC) that uses a subranging conversion technique. High accuracy at a 1-MHz conversion rate is obtained with novel circuits developed for a track-and-hold device, a residue amplifier, and a digital-to-analog converter. Design aspects of these key functional circuits are presented. A prototype ADC was fabricated on a printed-circuit board and tested. Curve-fit test results show that up to 100 kHz, the effective bits decrease to 14 bits due to wideband noise. However, signal bandwidth is commonly restricted in spectrum analysis, so a dynamic range of over 96 dB can be obtained.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130750091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The statistical noise analyzer (SNA) was designed to analyze very-low-frequency (VLF)/low-frequency (LF) highly impulsive atmospheric electromagnetic noise, which is largely produced by lightning discharges. The statistical noise analyzer portable (SNAP) laboratory model is the second generation of the original SNA. In addition to the original SNA functions, the SNAP lab model provides a prototype for a compatible, deployable system that will allow expanded remote data collection and more detailed laboratory analysis of VLF/LF noise. Real-time noise data from a VLF/LF antenna system is input to the receiver/sampling unit. The unit then bandlimits the signal, detects its envelope, and outputs a digital representation of the data. The resulting digital data are inputted electronically into the SNAP computer for statistical analysis. The SNAP lab model performs statistical analyses, and the results can be stored in a file, printed, displayed on PC CRT, or plotted.<>
{"title":"SNAP: VLF/LF statistical noise analyzer","authors":"J. A. Neubert","doi":"10.1109/IMTC.1989.36894","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36894","url":null,"abstract":"The statistical noise analyzer (SNA) was designed to analyze very-low-frequency (VLF)/low-frequency (LF) highly impulsive atmospheric electromagnetic noise, which is largely produced by lightning discharges. The statistical noise analyzer portable (SNAP) laboratory model is the second generation of the original SNA. In addition to the original SNA functions, the SNAP lab model provides a prototype for a compatible, deployable system that will allow expanded remote data collection and more detailed laboratory analysis of VLF/LF noise. Real-time noise data from a VLF/LF antenna system is input to the receiver/sampling unit. The unit then bandlimits the signal, detects its envelope, and outputs a digital representation of the data. The resulting digital data are inputted electronically into the SNAP computer for statistical analysis. The SNAP lab model performs statistical analyses, and the results can be stored in a file, printed, displayed on PC CRT, or plotted.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"257 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115332587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. J. Turnell, M. E. de Morais, N.S. do Nascimento, A. Ramos
The authors present the design and implementation of a three-phase power transducer based on microprocessor technology. The transducer is intended for applications in which fast response time and flexible operation are important. This transducer can produce its outputs after each cycle (16.6 ms for 60-Hz transmission systems). The transducer is considered flexible because it is capable of supplying other output beyond simple three-phase power, voltage, and current. The theory of operation of the transducer, its present limitations, and proposals for future performance enhancements are presented.<>
{"title":"A microprocessor-based three phase power transducer","authors":"D. J. Turnell, M. E. de Morais, N.S. do Nascimento, A. Ramos","doi":"10.1109/IMTC.1989.36829","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36829","url":null,"abstract":"The authors present the design and implementation of a three-phase power transducer based on microprocessor technology. The transducer is intended for applications in which fast response time and flexible operation are important. This transducer can produce its outputs after each cycle (16.6 ms for 60-Hz transmission systems). The transducer is considered flexible because it is capable of supplying other output beyond simple three-phase power, voltage, and current. The theory of operation of the transducer, its present limitations, and proposals for future performance enhancements are presented.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115722424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A major figure of merit in digital scopes is the size of the acquisition memory. The author discusses the importance of this specification by examining a series of advantages directly traceable to long memories. Long records provide higher sampling rates, higher single-shot bandwidth, vastly reduced aliasing effects, substitution for inaccurate glitch detectors, improved signal-to-noise ratios, wide dynamic range in the frequency domain, and high signal processing accuracy. The author discusses sampling-rate variation, acquisition of long-duration events, glitch detection, accuracy of pulse waveform measurements, and waveform reconstruction and distortion.<>
{"title":"Advantages of long memories","authors":"M. Schumacher","doi":"10.1109/IMTC.1989.36841","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36841","url":null,"abstract":"A major figure of merit in digital scopes is the size of the acquisition memory. The author discusses the importance of this specification by examining a series of advantages directly traceable to long memories. Long records provide higher sampling rates, higher single-shot bandwidth, vastly reduced aliasing effects, substitution for inaccurate glitch detectors, improved signal-to-noise ratios, wide dynamic range in the frequency domain, and high signal processing accuracy. The author discusses sampling-rate variation, acquisition of long-duration events, glitch detection, accuracy of pulse waveform measurements, and waveform reconstruction and distortion.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116485964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A method for estimating and measuring the probability density function (PDF) of random signals is derived. The method is based on a new representation of P.M. Woodward's theorem (1952), and has been tested in practice with good results. A new proof of Woodward's theorem is presented which includes the linear mean-square estimator and an upper bound on the error of the estimation based on Papoulis' inequality. The experimental setup for measuring the PDF is a simple one, consisting of a frequency modulation and a spectrum analyzer. The theory assures an error smaller than 0.08% for a modulating index of ten or more.<>
{"title":"Measurement of the probability density function of communication signals","authors":"M.S. Alencar","doi":"10.1109/IMTC.1989.36913","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36913","url":null,"abstract":"A method for estimating and measuring the probability density function (PDF) of random signals is derived. The method is based on a new representation of P.M. Woodward's theorem (1952), and has been tested in practice with good results. A new proof of Woodward's theorem is presented which includes the linear mean-square estimator and an upper bound on the error of the estimation based on Papoulis' inequality. The experimental setup for measuring the PDF is a simple one, consisting of a frequency modulation and a spectrum analyzer. The theory assures an error smaller than 0.08% for a modulating index of ten or more.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114518820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The authors show how a microprocessor can be used to provide the accuracy and flexibility that is required for a general-purpose industrial pH measurement system. Important features considered are automatic, precise temperature compensation with a low-cost temperature sensor, automatic compensation for system offsets and drift, and diagnostics from the front panel. A systematic design procedure that includes specifications, a theoretical analysis of error sources, careful consideration of important design criteria, and the system hardware and software design is described. A special technique of multiplexing a digital-to-analog converter for analog-to-digital conversion and output monitoring is used to keep overall cost low. A nonvolatile memory is used to store the calibration constants. A prototype has been built, and the results obtained under simulated and actual conditions are discussed.<>
{"title":"Microprocessor based pH monitoring and transmitting system","authors":"H. G. Rotithor, F. Trutt","doi":"10.1109/IMTC.1989.36837","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36837","url":null,"abstract":"The authors show how a microprocessor can be used to provide the accuracy and flexibility that is required for a general-purpose industrial pH measurement system. Important features considered are automatic, precise temperature compensation with a low-cost temperature sensor, automatic compensation for system offsets and drift, and diagnostics from the front panel. A systematic design procedure that includes specifications, a theoretical analysis of error sources, careful consideration of important design criteria, and the system hardware and software design is described. A special technique of multiplexing a digital-to-analog converter for analog-to-digital conversion and output monitoring is used to keep overall cost low. A nonvolatile memory is used to store the calibration constants. A prototype has been built, and the results obtained under simulated and actual conditions are discussed.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129445819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A floating-window algorithm is described that performs a triggering function that detects changes in the voltage waveform which can disrupt sensitive electronic loads. The proposed algorithm is an extension of a digital equivalent of G.W.Allen's (see IEEE Trans. Power Appl. Syst., vol. PAS-90, p.2604-9, May 1971) concept of an ideal-template-matching triggering mechanism, in which the digitized samples of a voltage waveform would be compared with the digitized values of an ideal waveform (in this case, the ideal sine wave). The proposed floating-window trigger mechanism uses each cycle of the AC waveform as a template for the succeeding cycle. Consequently, it triggers on a change in the shape of the voltage wave form. The proposed triggering function can be used to capture digitally sampled power line disturbances so their cause can be identified and corrected.<>
{"title":"A floating-window algorithm for detecting certain power line faults that disrupt sensitive electronic loads","authors":"A. McEachern","doi":"10.1109/IMTC.1989.36868","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36868","url":null,"abstract":"A floating-window algorithm is described that performs a triggering function that detects changes in the voltage waveform which can disrupt sensitive electronic loads. The proposed algorithm is an extension of a digital equivalent of G.W.Allen's (see IEEE Trans. Power Appl. Syst., vol. PAS-90, p.2604-9, May 1971) concept of an ideal-template-matching triggering mechanism, in which the digitized samples of a voltage waveform would be compared with the digitized values of an ideal waveform (in this case, the ideal sine wave). The proposed floating-window trigger mechanism uses each cycle of the AC waveform as a template for the succeeding cycle. Consequently, it triggers on a change in the shape of the voltage wave form. The proposed triggering function can be used to capture digitally sampled power line disturbances so their cause can be identified and corrected.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129527355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The author describes a digitally implemented coherent sweep generator, i.e. a sweep generator in which sweep rate, start frequency and start phase can be specified. By carrying out a digital integration twice, using a counter and an accumulator as the integrators, the quadratic phase function of a linear sweep is produced. The desired start frequency and start phase are introduced by presetting the counter and accumulator, respectively. The mod (2 pi ) of the quadratic phase function is extracted and used as address for a sine lookup table whose output is applied to a digital-to-analog converter. The system is capable of producing sweep signals from DC up to the lower MHz range, and the sweep rate can be varied over several orders of magnitude. By operating several digital sweep generators from the same clock, multiple coherent sweep signals can be produced. The digital sweep generator has been implemented with transistor-transistor logic, and generated waveforms are presented.<>
{"title":"Digitally based coherent sweep generator","authors":"P. Pedersen","doi":"10.1109/IMTC.1989.36860","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36860","url":null,"abstract":"The author describes a digitally implemented coherent sweep generator, i.e. a sweep generator in which sweep rate, start frequency and start phase can be specified. By carrying out a digital integration twice, using a counter and an accumulator as the integrators, the quadratic phase function of a linear sweep is produced. The desired start frequency and start phase are introduced by presetting the counter and accumulator, respectively. The mod (2 pi ) of the quadratic phase function is extracted and used as address for a sine lookup table whose output is applied to a digital-to-analog converter. The system is capable of producing sweep signals from DC up to the lower MHz range, and the sweep rate can be varied over several orders of magnitude. By operating several digital sweep generators from the same clock, multiple coherent sweep signals can be produced. The digital sweep generator has been implemented with transistor-transistor logic, and generated waveforms are presented.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129372780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inversion of the mathematical model is intrinsic to any measurement process, and the numerical complexity of this operation grows with the functional flexibility, accuracy, and speed of measurement. A special case of model inversion, namely, measurement signal reconstruction, is studied, using a linear model of the relationship between two scalar signals. Being numerically ill-conditioned, the reconstruction requires regularization, and reconstruction are classified into six groups according to the mechanism of regularization on which they are based. The six groups are: direct, variational, probabilistic, iterative, parametric, and transform methods.<>
{"title":"Unified approach to measurement signal reconstruction","authors":"R. Morawski","doi":"10.1109/IMTC.1989.36901","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36901","url":null,"abstract":"Inversion of the mathematical model is intrinsic to any measurement process, and the numerical complexity of this operation grows with the functional flexibility, accuracy, and speed of measurement. A special case of model inversion, namely, measurement signal reconstruction, is studied, using a linear model of the relationship between two scalar signals. Being numerically ill-conditioned, the reconstruction requires regularization, and reconstruction are classified into six groups according to the mechanism of regularization on which they are based. The six groups are: direct, variational, probabilistic, iterative, parametric, and transform methods.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125868400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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