Moisture Content in Drying Wood Using Direct Scanning Gamma-Ray Densitometry

Authors

  • John R. Davis
  • Jugo Ilic
  • Peter Wells

Keywords:

Gamma-ray attenuation, wood densitometry, moisture content, shrinkage

Abstract

The distribution of moisture content in specimens of Eucalyptus regnans at various stages of drying from the green state has been measured using a direct scanning gamma-ray densitometer. Densitometry results obtained using 59.5 keV gamma-ray photons were compared with data obtained from matched specimens using a conventional slicing and weighing technique. Preliminary results of a shrinkage distribution analysis are presented for the first time. A detailed discussion of the theoretical and experimental aspects of the scanning densitometry technique is given together with a description of the instrument constructed for this work.

References

Chafe, S. C. 1985. The distribution and interrelationship of collapse, volumetric shrinkage, moisture content, and density in trees of Eucalyptus regnansF. Muell. Wood Sci. Technol. 19:329-345.nCown, D. J., and B. G. Clement. 1983. A wood densitometer using direct scanning with X-rays. Wood Sci. Technol. 17:91-99.nCullen, D. E., M. H. Chen, J. H. Hubbell, S. T. Perkins, E. F. Plechaty, J. A. Rathkopf, and J. H. Scofield. 1989. Tables and graphs of photon-interaction cross-sections from 10eV to 100GeV derived from the LLNL evaluated Photon Data Library (EPDL), UCRL-50400, Vol. 6.4.nIlic, J. 1983. The development of rapid automatic systems for measurement of wood anatomical characteristics and their application to wood properties. M. App. Sci. thesis (unpublished), Chisholm Institute of Technology, Caulfield East, Victoria, Australia.nJackson, D. F., and D. J. Hawkes. 1981. X-ray attenuation coefficients of elements and mixtures. Physics Reports 70:169-233.nKingston, R. S. T., and C. J. E. Risdon. 1961. Shrinkage and density of Australian and other South-West Pacific woods. CSIRO Div. For. Prods., Tech. Paper No. 13, Melbourne, Australia.nLaufenberg, T. L. 1986. Using gamma radiation to measure density gradients in reconstituted wood products. Forest Prod. J. 36:59-62.nSpolek, G. A., and O. A. Plumb. 1981. Capillary pressure in softwoods. Wood Sci. Technol. 15:189-199.nWinistorfer, P. M., W. C. Davis, and W. W. Moschler. 1986. A direct scanning densitometer to measure wood composite products. Forest Prod. J. 36:82-86.n

Downloads

Published

2007-06-28

Issue

Number 2 / April 1993

Section

Research Contributions

License

The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:

1. All proprietary rights other than copyright, such as patent rights.

2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.

3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.