Development of Weight-Moisture Grader for Wood by Microwave Sensor

1.木材定量水分小型化传感器的研制本研究采用高功率、宽量程的压控振荡器，提高S/N比，用A/D、D/A转换器控制计算机对频率漂移和衰减进行高速检测和平均，并利用微波腔同时测量木材纸张的定量(标准偏差2.5g/m~2)和水分(标准偏差0.125 g/m~2)。测量软件采用C语言编写，便于安装到只读存储器电路中。为此，我们研制了一种小型化、轻便的样机测试仪。木材定量含水率分级机扫描传感器的研制虽然我们可以用小尺寸测试仪进行点测量，但我们验证了湿度仪移动木材并测量木材定量含水率分布的可能性。…更多地使用木头。特别是，我们改变了腔的大小以获得合适的空间分辨率，并获得了2厘米的空间分辨率。我们研制了一种与木材方向无关的、测量木材水分直径为2厘米的空间平均值的微波腔。通过在直线移动工作台上移动木材，得到了木材重量和含水率的全貌。木材定量含水率分级机传感器的研制。最后，用电子扫描代替机械扫描对木材含水率分级机进行了基本测量。也就是说，我们制作了一个传感器系统，将四个到八个不同谐振频率的微波腔结合在一起，用一个分频器和一个合并器来分离和统一一个微波振荡器提供的微波功率，用一个探测器来检测发射的微波。因此，我们可以通过将传感器头放在木材上来瞬时测量木材的水分分布。较少

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