Fecht, H. J. and Johnson, W. L. (1991) A conceptual approach for noncontact calorimetry in space. Review of Scientific Instruments, 62 (5). pp. 1299-1303. ISSN 0034-6748 http://resolver.caltech.edu/CaltechAUTHORS:20120419-081058620
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A concept is developed and described which allows to measure the heat capacity and the effective thermal conductivity of stable and undercooled liquid metals and alloys in an electromagnetic levitation apparatus. We propose to use an ac pulse heating method which is used nowadays as a standard technique for precision measurement of low temperature heat capacities. The ideal process parameters including the drop diameter D, temperature T, and frequency of measurement ω can be optimized when the following relations hold for the external and internal relaxation time constants τ_1 and τ_2, respectively: ωτ_1≳10 and ωτ_2<0.1. Then heat capacity data can be obtained with an accuracy of better than 1% with D about 5 to 10 mm, T between 1200 and 1800 K and ω between 0.1 and 1 Hz for typical metals and alloys.
|Additional Information:||© 1991 American Institute of Physics. Received 30 April 1990; accepted for publication 17 September 1990. Useful discussions with Dr. D. Herlach (DLR), Dr. R. Willnecker (DLR), and Dr. M. C. Lee (NASA), and the financial support by NASA (NAS 496954MG3203550) are gratefully acknowledged|
|Subject Keywords:||LIQUID METALS, THERMAL CONDUCTIVITY, SPECIFIC HEAT, SPACE, LEVITATION, CALORIMETRY, MEASURING METHODS, TEMPERATURE DEPENDENCE, VERY HIGH TEMPERATURE, ELECTROMAGNETIC FIELDS|
|Classification Code:||PACS: 07.20.Fw, 72.15.Eb, 65.40.-b, 65.60.+a, 65.80.-g, 95.55.Sh|
|Official Citation:||A conceptual approach for noncontact calorimetry in space H. J. Fecht and W. L. Johnson Rev. Sci. Instrum. 62, 1299 (1991); http://dx.doi.org/10.1063/1.1142488|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||19 Apr 2012 17:47|
|Last Modified:||26 Dec 2012 15:05|
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