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

高频水分计自动密度校正和水分梯度测量功能的开发

• 批准号: 07556040
• 负责人: SOBUE Nobuo
• 金额: $ 2.43万
• 依托单位: SHIZUOKA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07556040/
• 关键词: High frequency moisture meter; Density correction; Measurement of moisture gradient; Electrode scanning; Simultaneous measurement of density and moisture content; Inverse solution; 自動密度補正; 水分傾斜測定機能; 電極間隔; 実効電界深度

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.

研究了高频水分仪密度校正和水分梯度测量功能的开发，提出了一种电极扫描法来测量水分梯度。在该方法中，测量了电容随电极距离的变化。电极扫描引起的电容变化C(D)定义为如下积分方程式：C(D)=*S(d，x)U(X)dx，其中S(d，x)为权函数，U(X)为水分梯度。为了求解这个方程，引入了一个线性联立方程。通过实验确定了具有不同水分梯度的模型试件的权函数，并对电容曲线与水分梯度的关系进行了模拟研究。结果表明：(1)在这些高频水分计中，电容对电极附近的水分状况非常敏感。(2)随着电极间距的增加，电容呈指数下降。(3)随着电极距离的增加，深部位置的相对灵敏度增加。(4)水分梯度反解不稳定，水分梯度再现不足。应该要求父亲进行数学处理。(5)结果的实际应用是对电容曲线的频谱模式进行分类。木材密度对高频水分仪的测量有很大影响。在这项研究中，提出了一种同时测定密度和水分含量的方法，并对以下算法进行了研究。Kollmann的密度-含水率图与水分计的读数相结合。这些值在两次或三次迭代中收敛，证实了所提出的算法的正确性。