Pub Date : 1968-07-01DOI: 10.1088/0022-3735/1/7/423
J Deer, K Ridgway, R Rupp
Two cadmium sulphide cells are mounted at the lower ends of vertical copper tubes holding lenses to concentrate light on the cells, and illuminated powder samples are placed above the upper ends of the tubes. The cells are included in the arms of a transformer bridge which is energized by 50 Hz alternating current. The bridge output may be examined either by a valve voltmeter, or used to drive an amplifier to provide a larger output. A response is obtained which is linear to within some 10% over the whole composition range for coarse granular powder mixtures of a wide range of colours.
{"title":"A simple and cheap photosensitive transformer bridge for the analysis of powder mixtures.","authors":"J Deer, K Ridgway, R Rupp","doi":"10.1088/0022-3735/1/7/423","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/423","url":null,"abstract":"Two cadmium sulphide cells are mounted at the lower ends of vertical copper tubes holding lenses to concentrate light on the cells, and illuminated powder samples are placed above the upper ends of the tubes. The cells are included in the arms of a transformer bridge which is energized by 50 Hz alternating current. The bridge output may be examined either by a valve voltmeter, or used to drive an amplifier to provide a larger output. A response is obtained which is linear to within some 10% over the whole composition range for coarse granular powder mixtures of a wide range of colours.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/423","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16778717","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 : 1968-07-01DOI: 10.1088/0022-3735/1/7/432
C Bell, C Birby, E Hutton, E Stubbs
A delay unit is described which is capable of producing time delays of from one microsecond to several milliseconds duration. The delay times may be selected at one microsecond intervals throughout the range. It has been designed to fit this specification but can easily be extended to produce longer delays. By suitable modification shorter delay times and increased time resolution may be obtained. The unit has a totally reproducible performance, is adaptable to other applications and is insensitive to external fields.
{"title":"A general purpose delay unit and its application to kinetic flash photolysis spectroscopy.","authors":"C Bell, C Birby, E Hutton, E Stubbs","doi":"10.1088/0022-3735/1/7/432","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/432","url":null,"abstract":"A delay unit is described which is capable of producing time delays of from one microsecond to several milliseconds duration. The delay times may be selected at one microsecond intervals throughout the range. It has been designed to fit this specification but can easily be extended to produce longer delays. By suitable modification shorter delay times and increased time resolution may be obtained. The unit has a totally reproducible performance, is adaptable to other applications and is insensitive to external fields.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/432","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16778718","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 : 1968-07-01DOI: 10.1088/0022-3735/1/7/201
D W Hill
This year, 1968, is the 50th anniversary of the formation of the Institute of Physics. (The Institute of Physics and The Physical Society was formed from the amalgamation of the two bodies.) In order to celebrate this Jubilee we are publishing a series of articles concerning various aspects of intrumentation over the last 50 years.
{"title":"Progress in medical instrumentation over the past fifty years.","authors":"D W Hill","doi":"10.1088/0022-3735/1/7/201","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/201","url":null,"abstract":"This year, 1968, is the 50th anniversary of the formation of the Institute of Physics. (The Institute of Physics and The Physical Society was formed from the amalgamation of the two bodies.) In order to celebrate this Jubilee we are publishing a series of articles concerning various aspects of intrumentation over the last 50 years.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15975850","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 : 1968-07-01DOI: 10.1088/0022-3735/1/7/435
T B Read
An instrument is described by which the absolute spectral power distribution of light sources can be displayed directly on a pen-recorder. It is based on a grating monochromator which is motor driven at a scanning rate of 100 nm min−1, and the variation with wavelength of the overall instrument response is automatically compensated by an electrical attenuator network connected to a multitapped potentiometer geared to the wavelength drive. The use of a diffusing screen for the entrance optics makes the output independent of source geometry, and allows an absolute scale calibration, with an error not exceeding 10%, to be obtained by means of a standard tungsten lamp.
{"title":"A scanning spectroradiometer.","authors":"T B Read","doi":"10.1088/0022-3735/1/7/435","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/435","url":null,"abstract":"An instrument is described by which the absolute spectral power distribution of light sources can be displayed directly on a pen-recorder. It is based on a grating monochromator which is motor driven at a scanning rate of 100 nm min−1, and the variation with wavelength of the overall instrument response is automatically compensated by an electrical attenuator network connected to a multitapped potentiometer geared to the wavelength drive. The use of a diffusing screen for the entrance optics makes the output independent of source geometry, and allows an absolute scale calibration, with an error not exceeding 10%, to be obtained by means of a standard tungsten lamp.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/435","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16778719","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 : 1968-07-01DOI: 10.1088/0022-3735/1/7/304
R E Burge, D F Garrard
The quality of images recorded photographically with electrons with energies from 7-60 keV is examined by measurements on the granularity of large areas exposed to a uniform optical density and the density profiles found in the images of sharp opaque edges. The work has been mainly carried out with Ilford Special Lantern Contrasty (SLC), Ilford Nuclear Research G5 and Kodak C-type DC3 emulsions. The granularity of SLC and G5 at 60 and 7 keV respectively has been examined over a range of densitometer scanning aperture diameters from 65 to 63 μm and these measurements are related to the corresponding correlation curves. Grain correlation is found for SLC at 60 kV extending over image regions about 15 μm in diameter; no correlation was found for G5 at 7 kV, or at 60 kV for which case a few measurements were also made. The changes in image granularity with electron energy were examined for SLC, G5 and two other nuclear emulsions using a scanning aperture 45 μm in diameter. Similar measurements on DC3 were limited to the energy range 7-20 keV. The detective quantum efficiencies were evaluated from the granularity measurements for all these emulsions. As examples of the results, over the energy range from 7-60 keV the values of detective quantum efficiency for G5 and SLC fell by factors of about 2 and 30 respectively. A comparison between observed and calculated values of the granularity shows reasonable agreement allowing for the assumptions made. The edge density profiles for SLC, G5 and DC3 were measured at 60 and 7 kV and, after the profiles are fitted to a function of exponential form, the corresponding modulation transfer functions (MTF) are considered. Inter-relating the measurements on the image granularity and the MTF allows the determination of the minimum detectable density difference corresponding to a Fourier image component of a given wavelength, and results are given for SLC at 60 kV and G5 at 7 kV. A comparison of these results shows that electron images of good quality may be recorded on G5 at low voltages and at readily realized image magnifications.
{"title":"The resolution of photographic emulsions for electrons in the energy range 7-60 kev.","authors":"R E Burge, D F Garrard","doi":"10.1088/0022-3735/1/7/304","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/304","url":null,"abstract":"The quality of images recorded photographically with electrons with energies from 7-60 keV is examined by measurements on the granularity of large areas exposed to a uniform optical density and the density profiles found in the images of sharp opaque edges. The work has been mainly carried out with Ilford Special Lantern Contrasty (SLC), Ilford Nuclear Research G5 and Kodak C-type DC3 emulsions. The granularity of SLC and G5 at 60 and 7 keV respectively has been examined over a range of densitometer scanning aperture diameters from 65 to 63 μm and these measurements are related to the corresponding correlation curves. Grain correlation is found for SLC at 60 kV extending over image regions about 15 μm in diameter; no correlation was found for G5 at 7 kV, or at 60 kV for which case a few measurements were also made. The changes in image granularity with electron energy were examined for SLC, G5 and two other nuclear emulsions using a scanning aperture 45 μm in diameter. Similar measurements on DC3 were limited to the energy range 7-20 keV. The detective quantum efficiencies were evaluated from the granularity measurements for all these emulsions. As examples of the results, over the energy range from 7-60 keV the values of detective quantum efficiency for G5 and SLC fell by factors of about 2 and 30 respectively. A comparison between observed and calculated values of the granularity shows reasonable agreement allowing for the assumptions made. The edge density profiles for SLC, G5 and DC3 were measured at 60 and 7 kV and, after the profiles are fitted to a function of exponential form, the corresponding modulation transfer functions (MTF) are considered. Inter-relating the measurements on the image granularity and the MTF allows the determination of the minimum detectable density difference corresponding to a Fourier image component of a given wavelength, and results are given for SLC at 60 kV and G5 at 7 kV. A comparison of these results shows that electron images of good quality may be recorded on G5 at low voltages and at readily realized image magnifications.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16778711","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 : 1968-07-01DOI: 10.1088/0022-3735/1/7/311
R N Ibbett, M J Selby
A digital recording system, with an integrating digital synchronous rectifier, has been built for use with a Fourier transform spectrometer. It exhibits good linearity and accurate integration of the output. A source of systematic error has been detected and overcome. The system is ideally suited for work with Fourier transform spectrometers which are capable of yielding high quality spectra.
{"title":"A digital recording system for Fourier transform spectrometry.","authors":"R N Ibbett, M J Selby","doi":"10.1088/0022-3735/1/7/311","DOIUrl":"https://doi.org/10.1088/0022-3735/1/7/311","url":null,"abstract":"A digital recording system, with an integrating digital synchronous rectifier, has been built for use with a Fourier transform spectrometer. It exhibits good linearity and accurate integration of the output. A source of systematic error has been detected and overcome. The system is ideally suited for work with Fourier transform spectrometers which are capable of yielding high quality spectra.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/7/311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16778713","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 : 1968-06-01DOI: 10.1088/0022-3735/1/6/316
D J White, A S Tickner
The construction is described of a special purpose instrument for photoelastic analysis with use of the frozen stress technique. Consideration is given to the methods of analysis employed with the microscope polariscope, and its limitations and potentialities in respect of oblique incidence analysis are discussed.
{"title":"A transmission microscope polarioscope for photoelastic analysis.","authors":"D J White, A S Tickner","doi":"10.1088/0022-3735/1/6/316","DOIUrl":"https://doi.org/10.1088/0022-3735/1/6/316","url":null,"abstract":"The construction is described of a special purpose instrument for photoelastic analysis with use of the frozen stress technique. Consideration is given to the methods of analysis employed with the microscope polariscope, and its limitations and potentialities in respect of oblique incidence analysis are discussed.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/6/316","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16735650","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 : 1968-06-01DOI: 10.1088/0022-3735/1/6/302
G S Plows, W C Nixon
High frequency cyclic voltages on a specimen surface have been studied pictorially, in the scanning electron microscope, by applying the principle of the sampling oscilloscope. The electron beam in the microscope column is pulsed, and the phase varied with respect to that of the waveform on the specimen. With 10 ns electron probe pulse length, a microcircuit voltage distribution, which is varying at 7 MHz, may apparently be stopped in time by this method of stroboscopy. Hence, a stationary picture may be obtained at any chosen phase within the cycle.
{"title":"Stroboscopic scanning electron microscopy.","authors":"G S Plows, W C Nixon","doi":"10.1088/0022-3735/1/6/302","DOIUrl":"https://doi.org/10.1088/0022-3735/1/6/302","url":null,"abstract":"High frequency cyclic voltages on a specimen surface have been studied pictorially, in the scanning electron microscope, by applying the principle of the sampling oscilloscope. The electron beam in the microscope column is pulsed, and the phase varied with respect to that of the waveform on the specimen. With 10 ns electron probe pulse length, a microcircuit voltage distribution, which is varying at 7 MHz, may apparently be stopped in time by this method of stroboscopy. Hence, a stationary picture may be obtained at any chosen phase within the cycle.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/6/302","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16735977","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 : 1968-06-01DOI: 10.1088/0022-3735/1/6/437
R Sauer
A sensitive guard-heater control system is described, which uses standard components, with a response to thermocouple e.m.f. changes of less than 0·1 μV, and a drift rate per hour of the same order if the ambient temperature remains constant to within 0·5 degC.
{"title":"Accurate temperature matching in calorimetry.","authors":"R Sauer","doi":"10.1088/0022-3735/1/6/437","DOIUrl":"https://doi.org/10.1088/0022-3735/1/6/437","url":null,"abstract":"A sensitive guard-heater control system is described, which uses standard components, with a response to thermocouple e.m.f. changes of less than 0·1 μV, and a drift rate per hour of the same order if the ambient temperature remains constant to within 0·5 degC.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/6/437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16735652","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 : 1968-06-01DOI: 10.1088/0022-3735/1/6/305
R J Collier, M A Collins, D G Moss
The design and performance of an X-band electron spin resonance spectrometer with a ruby maser preamplifier is discussed, and the practical improvement in sensitivity due to the maser was found to be 3. Some discussions on the limitations and sensitivity of the spectrometer are also made.
{"title":"An X-band electron spin resonance spectrometer with a ruby maser preamplifier.","authors":"R J Collier, M A Collins, D G Moss","doi":"10.1088/0022-3735/1/6/305","DOIUrl":"https://doi.org/10.1088/0022-3735/1/6/305","url":null,"abstract":"The design and performance of an X-band electron spin resonance spectrometer with a ruby maser preamplifier is discussed, and the practical improvement in sensitivity due to the maser was found to be 3. Some discussions on the limitations and sensitivity of the spectrometer are also made.","PeriodicalId":16983,"journal":{"name":"Journal of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1968-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/0022-3735/1/6/305","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15404653","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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