Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671187
D. Allan, M. Weiss, T. K. Peppler
Because of the increased need for better clock performance than is currently available, this paper addresses some fundamental questions regarding clock metrology. Heretofore, most work has focussed on improving the clocks to meet the increased need. Though this is fundamental and will be addressed in the paper, we will also show that significant gains are available through the algoritbms which process the clock readings and through international comparisons now available via satellite. Proper algorithms for processing seem to be more important than the proportionate attention generally given them. In fact, to date, the only way we have been able to investigate some of the long-term performance aspects of the millisecond pulsar, ESR 1937+21, is by using such optimization algorithms. Since there are indications in the pulsar data of variations which could be explained as arising from the influence of gravity waves, these long-term stability studies take on a new importance. Years of study will probably be necessary to confirm these initial indications, but clearly improved long-term stability of earth-bound clock systems would significantly assist this study.
{"title":"In search of the best clock","authors":"D. Allan, M. Weiss, T. K. Peppler","doi":"10.1109/CPEM.1988.671187","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671187","url":null,"abstract":"Because of the increased need for better clock performance than is currently available, this paper addresses some fundamental questions regarding clock metrology. Heretofore, most work has focussed on improving the clocks to meet the increased need. Though this is fundamental and will be addressed in the paper, we will also show that significant gains are available through the algoritbms which process the clock readings and through international comparisons now available via satellite. Proper algorithms for processing seem to be more important than the proportionate attention generally given them. In fact, to date, the only way we have been able to investigate some of the long-term performance aspects of the millisecond pulsar, ESR 1937+21, is by using such optimization algorithms. Since there are indications in the pulsar data of variations which could be explained as arising from the influence of gravity waves, these long-term stability studies take on a new importance. Years of study will probably be necessary to confirm these initial indications, but clearly improved long-term stability of earth-bound clock systems would significantly assist this study.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131665558","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671331
M. E. Cage, R. Dziuba, R. Elmquist, G. Jones, P. T. Olsen, W. Phillips, J. Q. Shields, R. Steiner, B. Taylor, E. Williams
Results from NBS experiments to realize the ohm and the watt, to determine the proton gyromagnetic ratio and the time dependence of the NBS ohm using the quantum Hall effect, and to maintain the NBS volt using the Josephson effect, are appropriately combined to obtain a highly accurate value of the fine-structure constant and of the quantized Hall resistance in SI units, and accurate values in SI units of the Josephson frequency to voltage quotient, Planck constant, and elementary charge.
{"title":"NBS Determination of the Fine-Structure Constant, and of the Quantized Hall Resistance and Josephson Frequency to Voltage Quotient in Si Units","authors":"M. E. Cage, R. Dziuba, R. Elmquist, G. Jones, P. T. Olsen, W. Phillips, J. Q. Shields, R. Steiner, B. Taylor, E. Williams","doi":"10.1109/CPEM.1988.671331","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671331","url":null,"abstract":"Results from NBS experiments to realize the ohm and the watt, to determine the proton gyromagnetic ratio and the time dependence of the NBS ohm using the quantum Hall effect, and to maintain the NBS volt using the Josephson effect, are appropriately combined to obtain a highly accurate value of the fine-structure constant and of the quantized Hall resistance in SI units, and accurate values in SI units of the Josephson frequency to voltage quotient, Planck constant, and elementary charge.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130386386","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671231
M. Abe, J. Nakazoe
A high stable(lppm) large dc current transformer is described. It is constructed using a current dividing network by shunt resistors and two magnetic-modulator-type ampere-turn comparators. The transform ratio of the transformer is independent of the current ratio in the shunt resistors.
{"title":"A Current-Dividing-Type High Stable DC Current Transformer Using a Magnetic Modulator","authors":"M. Abe, J. Nakazoe","doi":"10.1109/CPEM.1988.671231","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671231","url":null,"abstract":"A high stable(lppm) large dc current transformer is described. It is constructed using a current dividing network by shunt resistors and two magnetic-modulator-type ampere-turn comparators. The transform ratio of the transformer is independent of the current ratio in the shunt resistors.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129990052","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671221
U. Stumper
A new four-port reflectometer for the determination of the complex relative permittivity of microwave materials at submillimeter wavelengths is described. Measurement results obtained with various low-loss solids at frequencies of about 380 GHz agree well with data taken from the literature or obtained as results of an international comparison measurement exercise.
{"title":"Measurement Of The Complex Permittivity Of Microwave Materials With A Submillimeter Waveguide Four-Port Reflectometer","authors":"U. Stumper","doi":"10.1109/CPEM.1988.671221","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671221","url":null,"abstract":"A new four-port reflectometer for the determination of the complex relative permittivity of microwave materials at submillimeter wavelengths is described. Measurement results obtained with various low-loss solids at frequencies of about 380 GHz agree well with data taken from the literature or obtained as results of an international comparison measurement exercise.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131172477","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671300
Deming Zhu, M. Wu, J. Hsia
A System has been designed for controlling, acquiring and storing the photoelectric signals for the reference reflectance spectrophotometer in the division of radiometric physics at the NBS. Based on the IBM-PC/XT computer system, the GPIB interface is chosen to connect with various instruments (such as, current amplifier, lock-in amplifier, digital voltmeter and programmable high voltage power supply etc.) The control and analysis program is written in the TBASIC programming language. This system can also be used to control several stepping motors, as well as to control the opening and closing of the shutters. This computer program can be used for both the visible spectrum region from 200 to 750 NM and the near infrared region from 750 to 2500 NM. In this paper, the reference reflectance spectrophotometer, the computer program, and the resutts of the performance test are described.
{"title":"A Controlling And Data Acquisition System For The Reference Diffuse Reflectance Spectrophotometer Based On The IBM-PC/XT Computer","authors":"Deming Zhu, M. Wu, J. Hsia","doi":"10.1109/CPEM.1988.671300","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671300","url":null,"abstract":"A System has been designed for controlling, acquiring and storing the photoelectric signals for the reference reflectance spectrophotometer in the division of radiometric physics at the NBS. Based on the IBM-PC/XT computer system, the GPIB interface is chosen to connect with various instruments (such as, current amplifier, lock-in amplifier, digital voltmeter and programmable high voltage power supply etc.) The control and analysis program is written in the TBASIC programming language. This system can also be used to control several stepping motors, as well as to control the opening and closing of the shutters. This computer program can be used for both the visible spectrum region from 200 to 750 NM and the near infrared region from 750 to 2500 NM. In this paper, the reference reflectance spectrophotometer, the computer program, and the resutts of the performance test are described.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"503 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134033162","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671336
R. Bergeest, M. Kahmann, M. Klonz, R. Zirpel, P. Miljanic, B. Stojanovic
A highly accurate ac power source for unity power factor with an expected total uncertainty of a few parts in 10/sup 6/ to be used in the power frequency range is described. The rms value of the output voltage is continuously readjusted to a precisely known dc reference voltage using a multijunction thermal converter. A reference current is derived from the output voltage using an accurately known reiistor. The output current of a transconductance amplifier is compared to this reference current by means of a current comparator and continuously readjusted.
{"title":"Development of the New PTB Highly Accurate AC Power Source","authors":"R. Bergeest, M. Kahmann, M. Klonz, R. Zirpel, P. Miljanic, B. Stojanovic","doi":"10.1109/CPEM.1988.671336","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671336","url":null,"abstract":"A highly accurate ac power source for unity power factor with an expected total uncertainty of a few parts in 10/sup 6/ to be used in the power frequency range is described. The rms value of the output voltage is continuously readjusted to a precisely known dc reference voltage using a multijunction thermal converter. A reference current is derived from the output voltage using an accurately known reiistor. The output current of a transconductance amplifier is compared to this reference current by means of a current comparator and continuously readjusted.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134600344","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671282
V. Kose, E. Fay, F. Melchert
Before 1900 the Electrical Measurement System in Germany was founded based on the "Law on electrical Units" from 1898. This paper describes the present status of the tasks and organization of the legal and the industrial metrology in the area of electricity in the Federal Republic of Germany and West Berlin. The "Deutscher Kalibrierdienst" DKD, which was founded 1977, assures traceability to national standards of measurements done in industry for quality control. The links of the German Electrical Measurement System to international organizations and institutions are given.
{"title":"Electrical Measurement System in the Federal Republic of Germany","authors":"V. Kose, E. Fay, F. Melchert","doi":"10.1109/CPEM.1988.671282","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671282","url":null,"abstract":"Before 1900 the Electrical Measurement System in Germany was founded based on the \"Law on electrical Units\" from 1898. This paper describes the present status of the tasks and organization of the legal and the industrial metrology in the area of electricity in the Federal Republic of Germany and West Berlin. The \"Deutscher Kalibrierdienst\" DKD, which was founded 1977, assures traceability to national standards of measurements done in industry for quality control. The links of the German Electrical Measurement System to international organizations and institutions are given.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134393825","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671185
T. Kinoshita
At present the fine structure constant /spl alpha/ can be determined with a precision of better than few parts in 10/sup 7/ in four independent ways. They are based on the ac Josephson effect, the quantized Hall effect, the muonium hfs, and the anomalous magnetic.moment of the electron. Further improvements of these results and their implications to physics and metrology will be discussed.
{"title":"Accuracy of the ftne structure constant","authors":"T. Kinoshita","doi":"10.1109/CPEM.1988.671185","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671185","url":null,"abstract":"At present the fine structure constant /spl alpha/ can be determined with a precision of better than few parts in 10/sup 7/ in four independent ways. They are based on the ac Josephson effect, the quantized Hall effect, the muonium hfs, and the anomalous magnetic.moment of the electron. Further improvements of these results and their implications to physics and metrology will be discussed.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132802214","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671265
K. Takahashi
{"title":"Convenient Error Estimating Method for Current Transformer Test System Using Current Comparator","authors":"K. Takahashi","doi":"10.1109/CPEM.1988.671265","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671265","url":null,"abstract":"","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"190 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114092766","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}
Pub Date : 1988-06-07DOI: 10.1109/CPEM.1988.671175
H. Seppa, T. Korkolainen, T. Ryhanen
The positive thermal feedback in a self-generating system is shown to convert thermally induced white noise into 1/f noise. According to this model the slope of the low frequency noise spectrum is very close to unity since the real component evacuates its heat into the three-dimensional space. The theory predicts that the 1/f noise exceeds white noise below the frequency characterizing both the geometric structure of the component and the thermal properties of the surroundings. Consequently, the uncertainty of the measurement is inversely proportional to the physical size of the component or the standard.
{"title":"1/f noise in electrical components caused by the positive thermal feedback in self-generating syste","authors":"H. Seppa, T. Korkolainen, T. Ryhanen","doi":"10.1109/CPEM.1988.671175","DOIUrl":"https://doi.org/10.1109/CPEM.1988.671175","url":null,"abstract":"The positive thermal feedback in a self-generating system is shown to convert thermally induced white noise into 1/f noise. According to this model the slope of the low frequency noise spectrum is very close to unity since the real component evacuates its heat into the three-dimensional space. The theory predicts that the 1/f noise exceeds white noise below the frequency characterizing both the geometric structure of the component and the thermal properties of the surroundings. Consequently, the uncertainty of the measurement is inversely proportional to the physical size of the component or the standard.","PeriodicalId":326579,"journal":{"name":"1988 Conference on Precision Electromagnetic Measurements","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116340294","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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