Ion-flow anemometer using high-voltage pulse

In order to measure stratospheric wind velocity, the technique of ion transit-time measurement is useful. However, it has some difficulties for conventional air-speed measurement. The principle of the proposed anemometer is that the injected ion cloud is accelerated by an electric field, and the induced current of a detector, which is placed between an emitter and a collector, is measured. The time period from an emitter to a detector is first measured as a reference without wind. Then, the difference between two time periods is calculated by using a microcomputer to obtain wind speed. The fundamental characteristics of the sensor part of this anemometer are examined by changing electrode size, material, and mutual distances. Some of the parameters affect the motion of the charge cloud markedly and the others less. The overall function as an anemometer seems to be satisfactory because of a good relation between measured signal and applied wind. The experimental results indicate the possibility of a fast response on wind velocity variation, although it is not yet confirmed.<>