Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-26T12:51:12.380Z Has data issue: false hasContentIssue false

Thermal Conduction Measurements of Materials using Microwave Energy

Published online by Cambridge University Press:  28 February 2011

R. E. Giedd
Affiliation:
Center for Scientific Research, Southwest Missouri State University, 901 South National Ave, Springfield, Mo. 65802
G. R. Giedd
Affiliation:
Center for Scientific Research, Southwest Missouri State University, 901 South National Ave, Springfield, Mo. 65802
Get access

Abstract

We have developed a new technique to measure the thermal conductivity of materials using microwave energy. A thermal wave is induced in a material of unknown thermal conductivity using a pulse of microwave energy. This energy is incident on one side of the material. The corresponding temperature rise of the opposite side of the material is measured. The thermal diffusivity of the material can then be determined in the same way as ‘laser flash’[1]. Some of the advantages of the microwave system are the relatively low cost of the magnetron compared to the high energy laser, easily variable pulse length, and accurate measurement of the reflected energy.

The microwave system consists of a 2.45 GHz magnetron that is pulse modulated to energies as high as 10 J. A typical pulse lasts for 1 ms with rise and fall times of 10µs. This is achieved by a high voltage source (5 – 8 kV at 1 – 2 A), switched by a high power, rf transmitting tube connected in the filament circuit of the magnetron.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Parker, W.J., Jenkins, R.J., Butler, C.P., and Abbott, G.L., J. Appl. Phys., 32, p16791684 (1961).Google Scholar
2. Berman, R., Thermal Conduction in Solids, Clarendon Press, Oxford, (1976).Google Scholar
3. Carslaw, H.S., Yeager, J.C., Conduction of Heat in Solids, Oxford U.P., England, (1959).Google Scholar
4. Danielson, G.C., Sidles, P.H., Thermal Conductivity 2, Ed. Tye, R.P., Academic Press, N.Y., p149168, (1969).Google Scholar
5. Brydsten, U., Backstrom, G., International J. Th. Phys., Vol. 4, No. 4, p369387, (1983).Google Scholar
6. Clark, L.M. III, Taylor, R.E., J. Appl. Phys., 46:2, p714719, (1975).Google Scholar
7. Koski, J.A., Pro. 8th Sym. for Thermophysical prop., Vol. 2, p94103, (1981).Google Scholar
8. Skolinik, M.I., Introduction to Radar Systems, Magraw Hill Book Co., N.Y., (1962).Google Scholar
9. Liboff, R.L., Dalman, G.C., Transmission Lines, Waveguides, and Smith Charts, Macmillan Pubishing Co., London, (1985).Google Scholar
10. Giedd, R.E., Onn, D.G., Thermal Conductivity 20, Ed. Yarbrough, D.W., Plenum press, N.Y., p339346, (1989).Google Scholar
11. Handbook of Chemistry and Physics, 55th ed., CRC press, (1975).Google Scholar