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Journal of Wood Science

, Volume 55, Issue 1, pp 69–73 | Cite as

Evaluation of moisture content distribution in wood by soft X-ray imaging

  • Takashi TanakaEmail author
  • Stavros Avramidis
  • Satoshi Shida
Note

Abstract

A technique for nondestructive evaluation of moisture content distribution in Japanese cedar (sugi) during drying using a newly developed soft X-ray digital microscope was investigated. Radial, tangential, and cross-sectional samples measuring 100 × 100 × 10 mm were cut from green sugi wood. Each sample was dried in several steps in an oven and upon completion of each step, the mass was recorded and a soft X-ray image was taken. The relationship between moisture content and the average grayscale value of the soft X-ray image at each step was linear. In addition, the linear regressions overlapped each other regardless of the sample sections. These results showed that soft X-ray images could accurately estimate the moisture content. Applying this relationship to a small section of each sample, the moisture content distribution was estimated from the image differential between the soft X-ray pictures obtained from the sample in question and the same sample in the oven-dried condition. Moisture content profi les for 10-mm-wide parts at the centers of the samples were also obtained. The shapes of the profiles supported the evaluation method used in this study.

Key words

Nondestructive evaluation Soft X-ray Moisture content distribution Drying Sugi 

References

  1. 1.
    Lindgren LO, Davis J, Wells P, Shadbolt P (1992) Non-destructive wood density distribution measurements using computed tomography. Holz Roh Werkst 50:295–299CrossRefGoogle Scholar
  2. 2.
    Wiberg P (1995) Moisture distribution changes during drying. Holz Roh Werkst 53:402CrossRefGoogle Scholar
  3. 3.
    Fromm JH, Sautter I, Matthies E, Kremer J, Schumacher P, Ganter C (2001) Xylem water content and wood density in spruce and oak trees detected by high-resolution computed tomography. Plant Physiol 127:416–425CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Davis J, Ilic J, Wells P (1993) Moisture content in drying wood using direct scanning gamma-ray densitometry. Wood Fiber Sci 25:153–162Google Scholar
  5. 5.
    Rosenkilde A, Glover P (2002) High resolution measurement of the surface layer moisture content during drying of wood using a novel magnetic resonance imaging technique. Holzforschung 56:312–317CrossRefGoogle Scholar
  6. 6.
    Simpson WT (1998) Relationship between speed of sound and moisture content of red oak and hard maple during drying. Wood Fiber Sci 30:405–413Google Scholar
  7. 7.
    Johansson J, Hagman O, Fjellner BA (2003) Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber. J Wood Sci 49:312–316CrossRefGoogle Scholar
  8. 8.
    Nakanishi TM, Okano T, Karakama I, Ishihara T, Matsubayashi M (1998) Three dimensional imaging of moisture in wood disk by neutron beam during drying process. Holzforschung 52:673–676CrossRefGoogle Scholar

Copyright information

© The Japan Wood Research Society 2008

Authors and Affiliations

  • Takashi Tanaka
    • 1
    Email author
  • Stavros Avramidis
    • 2
  • Satoshi Shida
    • 1
  1. 1.Biomaterial Sciences Department, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
  2. 2.Department of Wood ScienceUniversity of British ColumbiaVancouverCanada

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