In the last 30 days

• Open/close Some aspects of research on thin solid films

  K M Greenland 1961 J. Sci. Instrum. 38 1 Tag this article

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  The practical importance of the structure of thin films deposited in vacuo and of the relationship between film and substrate is illustrated by description of a number of new thin-film devices. A brief history of research on thin films leads to a survey of some recent work on the nucleation, growth and structure of films examined by electron and field emission microscopy, and on the measurement of film-substrate binding energy.

• Open/close The Control of Humidity by Saturated Salt Solutions

  F E M O'Brien 1948 J. Sci. Instrum. 25 73 Tag this article

  Article References Full text PDF (258 KB)

  A table of data gives percentage relative humidities over saturated solutions of eighty-eight different salts or salt mixtures. Remarks on the suitability of these solutions for humidity control are included.

• Open/close Phase-Contrast Microscopy

  C R Burch and J P P Stock 1942 J. Sci. Instrum. 19 71 Tag this article

  Article References Full text PDF (632 KB)

  Slight optical non-homogeneities in certain transparent specimens are usually rendered visible by putting the specimen out of focus. One then sees not the non-homogeneities themselves, but the focal spots and lines they produce. Zernike's method of phase-contrast illumination, on the other hand, provides the maximum contrast when the specimen is accurately in focus, so that what is seen bears a closer resemblance to what is "really there". A simple method of adapting an ordinary microscope for phase-contrast is described, together with the preparation of a test-slide to check its performance. The method has proved helpful in studies of the interaction between leucocytes and mobile organisms.

• Open/close Construction and operation of a simple flame-ionization detector for gas chromatography

  D J Morgan 1961 J. Sci. Instrum. 38 501 Tag this article

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  The construction of a cheap and simple gas chromatograph incorporating a flame-ionization detector is described.

• Open/close The conversion factor for kX units to ångström units

  W L Bragg 1947 J. Sci. Instrum. 24 27 Tag this article

  Article References Full text PDF (132 KB)

• Open/close The preparation and performance of thin film thermocouples

  R Marshall et al 1966 J. Sci. Instrum. 43 144 Tag this article

  Article References Full text PDF (543 KB)

  The preparation of simple thin film thermocouples by vacuum deposition is described. Thermocouple combinations were constructed from nickel, iron, copper, constantan, Chromel and Alumel, the metal elements being evaporated by using conventional resistance heating methods and the alloys by flash evaporation. Measurements of temperature against e.m.f. for metal element combinations gave almost bulk metal characteristics; for example, a thermal e.m.f. value of 0.027 mv degC ^-1 is obtained for a Ni-Fe combination. However, for alloy-metal element film combinations, while bulk material thermal e.m.f. values were not obtained, a high order of sensitivity was measured; for example a copper-constantan combination gave 0.035 mv degC ^-1. Results indicate that the maximum thermal e.m.f. of a thin film thermocouple is obtained when the film thickness of each element is greater than 2500 Å. Ni-Fe pairs prepared under given conditions gave stable thermocouples reproducible to ±2 degC at 250°C.

• Open/close Modified Sawyer and Tower circuit for the investigation of ferroelectric samples

  J K Sinha 1965 J. Sci. Instrum. 42 696 Tag this article

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  A modification to the Sawyer and Tower circuit is proposed which removes two of the major drawbacks inherent in the original, namely the introduction of phase differences between the voltages on the X and Y plates of the oscilloscope arising because of the different circuit components used in the two branches and also because of the finite conductivity of the sample under investigation.