| 摘要 |
PURPOSE:To detect the wind direction at minute wind speed from the detection output and the mean value of the whole by providing a plurality of wind detectors to a respective direction so that the directional ranges are partly overlapped in the case of a wind direction detector. CONSTITUTION:The wind detectors 4A-4D of the same constitution with a thermal anemometer containing inside a heating temperature sensor and a nonheaing temperature sensor are attached to the support 3 in the different directions each other. The wind detector is blocked at one end and provided with small openings 16 thus having the directivity in the range of a constant angle theta. The angle theta is so selected that the range of said directivity is partially overlapped between the adjacent detectors. When the wind blows from one direction, the output of the detector on the upstream side is always bigger than the mean value of the four detection output. By comparing these the wind direction can be measured even at minute wind speed. |
