Advertisement

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 Tanaka
  • 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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

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
  • 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

Personalised recommendations