【摘要】 单一平面电容传感器是用来测量木材含水率的高精度仪器,属于具有任意结构形状的电容传感器的特例。为研究单一平面传感器数学模型的数值解法,以一种设定了具体尺寸的单一平面电容传感器为例,利用数值分析的一个数值方法——差分离散格式,对笔者前期建立的任意结构形状的电容传感器的偏微分方程数学模型构造了便于计算和研究的离散近似模型。利用该近似模型对单一平面电容传感器的工作状况进行分析,得到了木材介电常数与传感器电容值的关系。更多还原

【Abstract】 Accurate mathematical models for capacitance sensor with an arbitrary shape structure are available.Single planar capacitance sensor is a kind of high-precision equipment which can be used to measure wood moisture content.It is a special capacitance sensor with an arbitrarily shaped structure.However,it is difficult to solve the partial differential equations involved in the mathematical model for analyzing the working conditions of capacitance sensors with an arbitrary shape structure.For a single planar capacitance sensor,its precise analytical solution cannot be resolved.Therefore,solving the mathematical model for a single planar capacitance sensor is the main objective of this paper.A single planar capacitance sensor with its specific size was taken as an example in this paper.Discretized differential numerical analysis method was applied to construct the discretized approximate model.The model was convenient to solve differential equations developed in the past.An approximate model is adopted to analyze working conditions of single planar capacitance sensors and to find the relationship between wood dielectric constant(ε) and the capacitance value (C) of capacitance sensors.Findings from this study can be applied to the practice of engineering and the method developed can be extended to single planar capacitance sensors of general size and structure.更多还原