Copper In Douglas-Fir and Associated Dielectric Changes

Authors

  • Olaf R. Knezevic
  • R. T. Lin

Keywords:

<i>Pseudotsuga menziesii</i>, dielectric constant, loss tangent, AC resistivity, wood preservation

Abstract

The dielectric constant, loss tangent, and AC resistivity of 60 Douglas-fir (Psendotsuga menziesii (Mirb.) Franco) heartwood specimens were determined at 100 Hz, 1 kHz, 50 kHz, and 100 kHz before and after treatment with copper sulphate solutions. The copper retentions, based on oven-dry weight before treatment, ranged from 1 to 7%.

Of the three electrical properties, AC resistivity changed most as a result of treatment. This change, a factor of 7, occurred at 100 Hz and with specimens at an estimated 20% moisture content. A statistical analysis showed even changes of this magnitude are insufficient to form a basis for a nondestructive method for estimating copper retention in wood.

References

Draper, N. R., and H. Smith. 1966. Applied regression analysis. John Wiley Sons, Inc., New York. 407 pp.nEwing, G. W. 1969. Instrumental methods of chemical analysis. McGraw-Hill, New York. 627 pp.nJames, W. L. 1966. Effects of wood preservatives on electric moisture meter readings. U.S. Dep. Agric., For. Serv., For. Prod. Lab., Res. Note FPL-0106. Madison, WI. Rev. August 1966. 12 pp.nKelsey, K. E., and L. N. Clark. 1956. The heat of sorption of water by wood. Aust. J. Appl. Sci. 7(2):160-175.nSkaar, C. 1949. The dielectric properties of wood at several radio frequencies. N.Y. State Coll. For., Tech. Publ. No. 69. 36 pp.nStamm, A. J., and W. K. Laughborough. 1934. Thermodynamics of the swelling of wood. J. Phys. Chem. 39(1):121-132.n

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Published

2007-06-05

Issue

Number 4 / Winter 1975

Section

Research Contributions

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