CAJ | 학술논문

木材中的水分对木材的性能有着决定性的影响，目前测量木材水分的方法多适用于小型木材的检测。然而，当树木被砍伐后，在加工前希望了解其内部水分状态，因此需要一种方法来检测大型原木的水分。该文设计了一种微型核磁共振(NMR)传感器，该传感器为圆柱型结构（直径为28 mm，长度为60 mm），测量区域位于传感器外侧，形成与传感器同轴的圆环。测量前，需在被测部位凿一个与传感器直径相当的孔。测量时传感器沿着孔壁测量即可获得对应位置的 NMR 参数信息。初步实验结果表明，该传感器可以分辨被测木材中自由水和束缚水的分布以及各部位水分的相对含量。
목재중적수분대목재적성능유착결정성적영향，목전측량목재수분적방법다괄용우소형목재적검측。연이，당수목피감벌후，재가공전희망료해기내부수분상태，인차수요일충방법래검측대형원목적수분。해문설계료일충미형핵자공진(NMR)전감기，해전감기위원주형결구（직경위28 mm，장도위60 mm），측량구역위우전감기외측，형성여전감기동축적원배。측량전，수재피측부위착일개여전감기직경상당적공。측량시전감기연착공벽측량즉가획득대응위치적 NMR 삼수신식。초보실험결과표명，해전감기가이분변피측목재중자유수화속박수적분포이급각부위수분적상대함량。
The content and distribution of water in wood affect its performance. So far, most technologies to measure water content/distribution can only be applied to small wood samples. A method to measure the water content inside large timber is urgently needed, given that information on water content/distribution inside the harvested timber is often required before the timber can be processed to products. In this work, a mini cylindrical NMR sensor (i.e., 28 mm in diameter and 60 mm in length) for measuring water content inside large timber was designed. The sensitive volume is a coaxial ring just outside of the sensor. For measurement, the sensor needs to be placed inside a hole drilled on the timber, which has a similar diameter with the sensor. By moving the sensor around the wall of the hole, the NMR parameters of the timber could be measured. Preliminary experimental results showed that the sensor can detect signals from both free water and the bound water in large timber, and such signals can be used to calculate relative water contents.