DEVELOPMENT OF THE FUNCTIONS FOR AUTOMATED DENSITY CORRECTION AND MOISTURE GRADIENT MEASUREMENT OF HIGH FREQUENCY MOISTURE METER

研究了高频湿度计密度校正和湿度梯度测量功能的开发。为了评估水分梯度，提出了一种电极扫描法。该方法测量了电容随电极距离的变化。电容曲线模式与水分梯度模式具有良好的相关性。电极扫描C (d)引起的电容变化定义为以下积分方程，C (d)=* S (d, x) U (x) dx，其中S （d, x）为权函数，U (x)为水分梯度。为了求解该方程，引入了线性联立方程。通过不同湿度梯度的模型试样，实验确定了其权重函数。对电容曲线与湿度梯度的关系进行了仿真研究。结果表明：(1)在高频湿度计中，电容对电极附近的湿度条件非常敏感。(2)电容随电极距离的增加呈指数递减。(3)随着电极距离的增加，深层相对灵敏度增大。(4)水汽梯度反解不稳定，水汽梯度重现不足。父亲的数学处理应该是必需的。(5)结果的实际应用是对电容曲线的谱图进行分类。木材密度对高频湿度计的测量影响很大。在这项研究中，提出了密度和水分含量的同时测定，并检验了以下算法。科尔曼密度-水分含量图与水分计读数的结果相结合。这些值在两次或三次迭代后收敛，并证实了所提算法的正确性。

Development of the functions for density correction and moisture gradient measurement of high frequency moisture meter was investigated.In order to evaluate the moisture gradient, an electrode scanning method was proposed. In this method, the capacitance change in function of electrode distance was measured. The capacitance curve pattern showed good correlation with the moisture gradient pattern.The capacitance change due to electrode scanning C (d) was defined as the following integral equation, C (d)=* S (d, x) U (x) dx, where S (d, x) is a weight function and U (x) is a moisture gradient. In order to solve this equation, a linear simultaneous equation was introduced. The weight function was experimentally determined from model specimens with different moisture gradient.Simulation research was made to investigate the relationship between the capacitance curve and the moisture gradient. The following results were obtained : (1) In these high frequency moisture meter, the capancitance is sensitive very much to the moisture condition near electrodes. (2) The capacitance decreases exponentially with increase of the electrode distance. (3) As the electrode distance increases, relative sensibility of deep position increases. (4) The inverse solution of moisture gradient was not stable, and the reproduce of the moisture gradient was insufficient. Father mathematical treatment should be required. (5) Practical application of the results is to classify the spectrum patterns of the capacitance curves.Wood density affects very much on the measurement of a high frequency moisture meters. In this research, a simultaneous determination of a density and moisture content was proposed, and the following algorism was examined. The Kollmann's density-moisture content figure was combined with the result of the reading of a moisture meter. These values converged in two or three times of iteration, and the propriety of the proposed algorism was confirmed.