Development of Weight-Moisture Grader for Wood by Microwave Sensor

1. 木材基重及含水率小型化传感器的研制。本研究采用大功率、宽量程的压控振荡器，提高信噪比，通过a /D和D/ a转换器控制计算机，采用高速法检测和平均频移和频衰减，并利用微波腔同时测量了木纸的基重（标准差2.5 g/m^2）和湿重（标准差0.125 g/m^2）。采用C语言编写了测量软件，便于安装到ROM电路中。因此，我们开发了一种小型化的便携式原型测试仪器。木材基重及含水率分级机扫描传感器的研制虽然我们可以用小型化的测试仪器%进行点测量，但我们检查了基重及含水率分级机移动木材的可能性以及测量木材基重及含水率分布的可能性。特别地，我们通过改变空腔尺寸来获得合适的空间分辨率，获得了2 cm的空间分辨率。我们研制了一个测量木材湿度的空间平均值的微波腔，其直径为2 cm，与木材方向无关。我们通过在直线移动台上移动木材，得到木材的基本重量和含水率的整体轮廓。木材基重及含水率分级机合金式传感器的研制。最后，用电扫描代替机械扫描对木材水分分级机进行了基本测量。即，我们制作了一个传感器系统，该系统具有4到8个不同谐振频率的微波腔，使用分频器和组合器将一个微波振荡器提供的微波功率分离和统一，并使用一个探测器检测发射的微波。因此，我们可以通过将传感器头部放在木材上，即时了解木材的水分分布。少

1. Development of downsize sensor of basis weight and moisture content for wood.In this study, we used a voltage-controlled oscillator with high power and wide range to, , increase S/N ratio, controlled a computer with A/D and D/A converters to detect and average frequency shifts and attenuations with high speed method, and measured the basis weight (standard deviation 2.5 g/m^2) and the moisture weight (standard deviation 0.125 g/m^2) of wood papers are measured simultaneously by using a microwave cavity. The software for the measurement was developed using C language, so that it was easy to install the software into ROM circuits. Therefore, we developed a downsize and potable prototype test instrument.2. Development of scanning sensor of basis weight and moisture content grader for woodAlthough we could make the point measurement by using the downsize test instrumen% we checked thi possibility of moisture grader to move a wood and measure the basis weight and moisture content distrib … More ution of the wood. In particular, we changed the cavity size to get suitable space resolution, and the'spatial resolution of 2 cm was obtained. We developed the microwave cavity which measured the spatial average with the diameter of 2 cm of the wood moisture and was independent of ligneous direction. We obtained the whole profile of basis weight and moisture content of wood by moving the wood on the straight moving table.3. Development of allay type sensor of basis weight and moisture content grader for wood.Finally, we made fundamental measurement of wood moisture grader by using electric scan instead of mechanical scan. Namely, we fabricated a sensor system that Ifas four to eight microwave cavities with different resonant frequencies, uses a divider and a combiner to separate and unite microwave powers provided by one microwave oscillator, and detect the transmitted microwave by using one detector. Therefore, we could the moisture distribution of a wood instantaneously by putting the sensor head on the wood. Less