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首页> 外文会议>International Symposium on Nondestructive Testing of Wood; 20000913-20000915; Sopron; HU >Effect of freezing-treatment on estimating free water distribution in wood by ultrasonic wave
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Effect of freezing-treatment on estimating free water distribution in wood by ultrasonic wave

机译：冷冻处理对超声波估计木材中自由水分布的影响

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摘要

A simple equation, which gives the ratio of air-dried part to water-saturated part as length, was proposed for estimating moisture distribution in wood by ultrasonic waves. In the region office water, the ultrasonic velocity is known to change slightly with moisture content It was examined bow freeze-treatrnent which changes free-water from liquid state to solid state, effects on ultrasonic velocity. It was confirmed that ultrasonic velocity was higher in freeze-treated specimens man in non-treated specimens at any moisture contents in the L, R, and T directions. With increasing moisture content, the ultrasonic velocity of non-treated specimen was approaching to the liquid water value (1.50km/s); on the other hand, that of freeze-treated was approaching to the solid water value (3.23km/s). In the R and T directions, the velocity difference between the non-treated specimens and the freezing-treated was significant in the region of free water, on the contrary, it was not in the region of bound water. These facts show that the velocity difference caused by freezing-treatment may indicate free water quantity in wood. In the verification of the proposed equation by model specimens, the calculated values with frozen specimens were closer to the pre-determined fixed values as a model than with non-treated specimens. The freeze-treatrnent is considered to be, therefore, effective on evaluating free water distribution in wood.
机译：提出了一个简单的方程式，该方程式给出了风干部分与水饱和部分的比率作为长度，用于通过超声波估计木材中的水分分布。已知在该区域的办公室水中，超声波速度会随水分含量而略有变化。已检查了弓形冷冻处理剂，该剂可将游离水从液态变为固态，从而影响超声波速度。可以肯定的是，在L，R和T方向上的任何水分含量下，冷冻处理的标本中的超声波速度在未处理的标本中较高。随着含水量的增加，未处理样品的超声波速度接近液态水值（1.50km / s）。另一方面，冷冻处理的水已接近固体水值（3.23km / s）。在R和T方向上，未处理样品和冷冻处理样品之间的速度差在自由水区域内显着，相反，在结合水区域内则不明显。这些事实表明，冷冻处理引起的速度差可能表示木材中的自由水量。在通过模型样本验证所提出的方程式时，与未处理的样本相比，冷冻样本的计算值更接近于作为模型的预定固定值。因此，认为冷冻处理对评估木材中的自由水分布有效。

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