| 摘要 |
A device for metering the angular position of a direction indicator, such as a wind direction indicator (10) mounted rotatably about an axis. The said device comprises the reference member (18) mounted rotationally about said axis and having driving means (44) for continuously rotating the reference member in a predetermined direction. The reference member (18) includes radiation beam directing means (46, 47) rotating with said reference member (18) so as to direct once each revolution a reference radiation beam and a measuring radiation beam from a radiation source (45) to a first radiation sensing means (26) and to a second radiation beam directing means (48) respectively. The said second directing means (48) is rotatable with the direction indicator (10) and adapted to direct the measuring radiation beam received from said first directing means (47) to second adjacent sensing means (14) generating a measuring signal when exposed to radiation. The said beam directing means may, for example, comprise fiber optical elements or minors and apertures. The time delay between generation of each reference signal and the succeeding measuring signal is a function of the angular position of the direction indicator (10), and the reference and measuring signal may be processed in a suitable electrical circuit for obtaining a direct indication of the said angular position. |
