摘要
基于驻波率测量原理的乔木茎体水分传感器,其测量装置由信号源、同轴传输线及双针平行不锈钢探针组成。乔木茎体的介电特性决定了同轴传输线两端电压差值(即传感器的输出电压)的大小,通过测量传感器的输出电压,可达到测量乔木茎体体积含水率的目的。通过两个实验来确定传感器的探针结构:模拟实验中研究了在不同有机试剂中探针长度对传感器输出电压的影响,实验中选取了不同的有机试剂来模拟不同体积含水率的乔木茎体。根据模拟实验数据,得出了传感器输出电压与探针长度的单调变化关系,选取了传感器的探针结构参数;对侧柏乔木茎体样本进行了干燥实验,得出传感器的输出电压与样本的体积含水率之间有较好的线性关系。
A probe based on standing wave ratio （SWR） to measure stem water content was presented. Two experiments were taken to study the configuration of probe： （1） Simulation experiment. Different organic solutions were chosen as the testing media to simulate the stem which contains water. The result shows that the output voltage changed lineally with the length change of the probe. （2） Calibration experiment. The sample of arborvitae was selected and the oven temperature was kept at 60℃ constantly. The result shows that the relationship between water content of stem and the output voltage was linear. It can be concluded that the probe we studied could be used to measure stem water content.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2009年第1期176-179,175,共5页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金资助项目(30671715)
国家科技支撑计划资助项目(2006BAD03A01)
林业公益性行业科研专项(200704040)
关键词
乔木茎体
含水率
传感器
探针结构
驻波率
Stem, Water content, Sensor, Probe configuration, Standing wave ratio
