Development of a Three Dimensional Anemometer Using an Alpha-Ray Probe.

本研究的目的是研制一种能够同时检测三维风速和风向的风速仪。要建造这种风速计的探头，必须满足两个关键要求。其一是离子从探头中心沿径向均匀流动。另一个。在平静的条件下，收集器电极被放置在X、Y和Z方向上以均匀地收集离子。采用共球形状作为风速计的探头。它由一个内球电极和8个Am-241α射线源和作为外球壳体一部分的收集器组成。该探头的气流测试系统由离子电流测量电路、A/D转换器、接口和PC机组成。风洞实验表明，该探头具有同时测量1m/S以下二维风速和风向的特点，有待进一步扩展到三维测量。

The purpose 6f this research is to develop the anemometer which has capable to detect three dimensional wind velocity and its direction simultaneously. Two key requirements should be satisfied to construct the probe of such anemometer. One is that ion flows uniformly in radial direction from a center of probe. The other. is that the collector electrodes are located to collect ions evenly in X-, Y-, and Z-directions under calm condition. The shape of co-sphere as the probe of the anemometer was employed. It was fabricated consisting of an inner spherical electrode attached with eight of Am-241 alpha -ray source and collectors which is a part of outer sphere shell. The test system of the probe in air flow was constructed consisting of measurement circuitry for Ionic current, an A/D transformer, an interface, and a personal computer. The wind tunnel experiments show that the fabricated probe has the characteristics of simultaneous detection both of two dimensional wind velocity and direction below 1 m/s. Further experiments needs to extend to three dimensional measurements.