Pub Date : 1989-12-01DOI: 10.1088/0022-3735/22/12/003
P. Phillips, T. Whall, E. Parker
The feasibility of using silicon diodes as the temperature sensors for thermoelectric power measurements below room temperature has been established. The advantages and disadvantages of diodes as compared to thermocouples for this purpose are discussed.
{"title":"The use of diode thermometers for thermoelectric power measurements","authors":"P. Phillips, T. Whall, E. Parker","doi":"10.1088/0022-3735/22/12/003","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/003","url":null,"abstract":"The feasibility of using silicon diodes as the temperature sensors for thermoelectric power measurements below room temperature has been established. The advantages and disadvantages of diodes as compared to thermocouples for this purpose are discussed.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"88 1","pages":"986-988"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80572172","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/007
B. Šantić, U. Desnica, N. Radic
A simple experimental method for determination of the Hall constant based on a continuous temperature variation is proposed. Measurements made with the procedure described are proven to be fast and accurate. Its basic advantages are simplicity and the ability to measure a larger number of points in a considerably shorter time than the standard method without a significant reduction in accuracy. It is convenient in the van der Pauw configuration, particularly for samples with asymmetrically positioned contacts, and/or for materials with a low mobility of free carriers.
{"title":"A simple method for determination of the Hall constant","authors":"B. Šantić, U. Desnica, N. Radic","doi":"10.1088/0022-3735/22/12/007","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/007","url":null,"abstract":"A simple experimental method for determination of the Hall constant based on a continuous temperature variation is proposed. Measurements made with the procedure described are proven to be fast and accurate. Its basic advantages are simplicity and the ability to measure a larger number of points in a considerably shorter time than the standard method without a significant reduction in accuracy. It is convenient in the van der Pauw configuration, particularly for samples with asymmetrically positioned contacts, and/or for materials with a low mobility of free carriers.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"57 1","pages":"997-1000"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91218354","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/009
F. Primdahl, B. Hernando, O. Nielsen, J. R. Petersen
A method for measuring the demagnetisation of fluxgate sensors is introduced and used to evaluate the demagnetising factors for four ring-core sensors having 5, 10, 15 and 20 wraps of magnetic core ribbon. The demagnetising factor is proportional to the number of wraps, and the noise is also proportional to the number of wraps except for the more noisy 5-wrap core. The estimated internal core noise was 1 pT RMS taking into consideration the demagnetising factor and the relative permeability of the core material.
{"title":"Demagnetising factor and noise in the fluxgate ring-core sensor","authors":"F. Primdahl, B. Hernando, O. Nielsen, J. R. Petersen","doi":"10.1088/0022-3735/22/12/009","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/009","url":null,"abstract":"A method for measuring the demagnetisation of fluxgate sensors is introduced and used to evaluate the demagnetising factors for four ring-core sensors having 5, 10, 15 and 20 wraps of magnetic core ribbon. The demagnetising factor is proportional to the number of wraps, and the noise is also proportional to the number of wraps except for the more noisy 5-wrap core. The estimated internal core noise was 1 pT RMS taking into consideration the demagnetising factor and the relative permeability of the core material.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"185 1","pages":"1004-1008"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85087165","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/012
S. Spark, A. Phelps
A 0.127 mm thick Mylar output window was developed for the highly tunable Strathclyde University electron cyclotron maser (ECM). This had no measurable millimetre-wave absorption in the W-band (75-110 GHz) frequency range and could withstand atmospheric pressure. Even for G-band (140-220 GHz) oscillation of the ECM the Mylar window was thin enough to avoid Fabry-Perot effects.
{"title":"Negligible absorption, broad passband, output window for a millimetre-wave electron cyclotron maser","authors":"S. Spark, A. Phelps","doi":"10.1088/0022-3735/22/12/012","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/012","url":null,"abstract":"A 0.127 mm thick Mylar output window was developed for the highly tunable Strathclyde University electron cyclotron maser (ECM). This had no measurable millimetre-wave absorption in the W-band (75-110 GHz) frequency range and could withstand atmospheric pressure. Even for G-band (140-220 GHz) oscillation of the ECM the Mylar window was thin enough to avoid Fabry-Perot effects.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"24 1","pages":"1015-1016"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78816868","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/022
W. Y. Leong, D. Robbins
A high background capacitance transient signal during DLTS measurement is reported and found to be an instrumental effect due to small fluctuations in the reverse bias on the diode under test. The authors confirm its observed behaviour from a consideration of small reverse bias fluctuations on the measured diode capacitance transient. They conclude that it is not related to deep trap centres.
{"title":"Anomalous DLTS signals due to small fluctuations in the reverse bias voltage on a Si diode","authors":"W. Y. Leong, D. Robbins","doi":"10.1088/0022-3735/22/12/022","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/022","url":null,"abstract":"A high background capacitance transient signal during DLTS measurement is reported and found to be an instrumental effect due to small fluctuations in the reverse bias on the diode under test. The authors confirm its observed behaviour from a consideration of small reverse bias fluctuations on the measured diode capacitance transient. They conclude that it is not related to deep trap centres.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"137 1","pages":"1051-1052"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79759905","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/014
D. A. Gorham, B. Pickthorne
The response of typical, commercial, silicon strain gauges exposed to a high intensity xenon flash source has been measured. Photovoltages are developed at the metal-semiconductor contacts and there is also a modulation of bulk conductivity. This conductivity change is of opposite sign for p-type and n-type gauges, and is due to a combination of thermal and optical effects. These results are a precautionary reminder that the magnitude of the response may be significant in some applications.
{"title":"Light sensitivity of silicon strain gauges","authors":"D. A. Gorham, B. Pickthorne","doi":"10.1088/0022-3735/22/12/014","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/014","url":null,"abstract":"The response of typical, commercial, silicon strain gauges exposed to a high intensity xenon flash source has been measured. Photovoltages are developed at the metal-semiconductor contacts and there is also a modulation of bulk conductivity. This conductivity change is of opposite sign for p-type and n-type gauges, and is due to a combination of thermal and optical effects. These results are a precautionary reminder that the magnitude of the response may be significant in some applications.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"37 1","pages":"1023-1025"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83248950","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/001
F. Luk, V. Huynh, W. North
A new method of surface roughness measurement was developed for use in a production environment. This method employs a microcomputer-based vision system to analyse the pattern of scattered light from the surface to derive a roughness parameter. The roughness parameters were obtained for a number of tool-steel samples which were ground to different roughnesses. A correlation curve was established by plotting the roughness parameters against the corresponding average surface roughness readings obtained from a stylus instrument. Similar correlation curves were produced for different materials such as brass and copper. Surface roughness measurement was also performed for specimens immersed in oil, a condition similar to that of a production environment. Some observable trends were found. The proposed method provides a fast and accurate means for measuring surface roughness. Its repeatability and versatility compares favourably with other methods.
{"title":"Measurement of surface roughness by a machine vision system","authors":"F. Luk, V. Huynh, W. North","doi":"10.1088/0022-3735/22/12/001","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/001","url":null,"abstract":"A new method of surface roughness measurement was developed for use in a production environment. This method employs a microcomputer-based vision system to analyse the pattern of scattered light from the surface to derive a roughness parameter. The roughness parameters were obtained for a number of tool-steel samples which were ground to different roughnesses. A correlation curve was established by plotting the roughness parameters against the corresponding average surface roughness readings obtained from a stylus instrument. Similar correlation curves were produced for different materials such as brass and copper. Surface roughness measurement was also performed for specimens immersed in oil, a condition similar to that of a production environment. Some observable trends were found. The proposed method provides a fast and accurate means for measuring surface roughness. Its repeatability and versatility compares favourably with other methods.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"54 1","pages":"977-980"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91017869","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/004
M. Ivanda, D. Djurek
The propagation of thermal waves in thin needle-shaped samples is described. The waves are generated by Joule power oscillation at one end of the sample. The amplitude and phase of the temperature oscillation are dependent upon thermal diffusivity. At low frequencies no phase shift appeared and only thermal conductivity was involved in the measurement. Specific heat was evaluated on the basis of thermal diffusivity and thermal conductivity.
{"title":"Thermal dispersion in AC calorimetry of needle-shaped specimens","authors":"M. Ivanda, D. Djurek","doi":"10.1088/0022-3735/22/12/004","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/004","url":null,"abstract":"The propagation of thermal waves in thin needle-shaped samples is described. The waves are generated by Joule power oscillation at one end of the sample. The amplitude and phase of the temperature oscillation are dependent upon thermal diffusivity. At low frequencies no phase shift appeared and only thermal conductivity was involved in the measurement. Specific heat was evaluated on the basis of thermal diffusivity and thermal conductivity.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"170 1","pages":"988-992"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89859881","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/010
O. Bostanjoglo, J. Kornitzky, R. Tornow
A high-velocity technique, capable of producing for the first time multi-frame short exposure time images in the electron microscope, is introduced. It is based on an electron image detector, consisting of a successively pulsed multichannel plate, acting as a fast shutter and a high-gain image amplifier, followed by a scintillator on positive potential as image converter. A frame-shifting plate capacitor, installed above the projector lens, places the succeeding images on unexposed areas of the multichannel plate, thus avoiding the long recovery time (milliseconds) of fired areas. Exposure times of 10-50 ns and delays >or approximately=100 ns between the shots are realised. Successive stages of laser pulse-induced crystallisation and evaporation of amorphous films are visualised with this new method.
{"title":"Nanosecond double-frame electron microscopy of fast phase transitions","authors":"O. Bostanjoglo, J. Kornitzky, R. Tornow","doi":"10.1088/0022-3735/22/12/010","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/010","url":null,"abstract":"A high-velocity technique, capable of producing for the first time multi-frame short exposure time images in the electron microscope, is introduced. It is based on an electron image detector, consisting of a successively pulsed multichannel plate, acting as a fast shutter and a high-gain image amplifier, followed by a scintillator on positive potential as image converter. A frame-shifting plate capacitor, installed above the projector lens, places the succeeding images on unexposed areas of the multichannel plate, thus avoiding the long recovery time (milliseconds) of fired areas. Exposure times of 10-50 ns and delays >or approximately=100 ns between the shots are realised. Successive stages of laser pulse-induced crystallisation and evaporation of amorphous films are visualised with this new method.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"27 1","pages":"1008-1011"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87470522","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 : 1989-12-01DOI: 10.1088/0022-3735/22/12/021
G. S. Bakken, D. Erskine, M. Murphy
A wind tunnel metabolism chamber is described which has a low (4.2 to 1) ratio of total to working volume to facilitate respiratory gas exchange measurements on unrestrained animals. Fine mesh screens smooth air flow to obtain 2% RMS turbulence and +or-5% uniformity. Simultaneous combinations of air temperature from -10 to 50 degrees C and wind from 0 to 3.6 m s-1 can be maintained indefinitely. A window admits simulated solar radiation to the working section.
{"title":"DESIGN NOTE: A wind tunnel metabolism chamber with small volume and good air flow characteristics","authors":"G. S. Bakken, D. Erskine, M. Murphy","doi":"10.1088/0022-3735/22/12/021","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/021","url":null,"abstract":"A wind tunnel metabolism chamber is described which has a low (4.2 to 1) ratio of total to working volume to facilitate respiratory gas exchange measurements on unrestrained animals. Fine mesh screens smooth air flow to obtain 2% RMS turbulence and +or-5% uniformity. Simultaneous combinations of air temperature from -10 to 50 degrees C and wind from 0 to 3.6 m s-1 can be maintained indefinitely. A window admits simulated solar radiation to the working section.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85683646","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：