| 摘要 |
In order to enable accurate readings of the draft of a vessel to be taken from deck level when there are waves on the water, a gas duct 9 is placed in the water and air is bubbled through the gas duct. The pressure in the gas duct is read using a manometer, and indicates the distance below the water surface of the exit opening of the gas duct. The gas duct terminates in a closed and vented damping chamber 3 which is connected to the surrounding water by a water duct 11 whose effective cross-sectional area is much less than that of the damping chamber. The water duct includes an admission chamber 12 with a separation plate 14 and an upstream water inlet 17 and a downstream water outlet 18, the apparatus 1 being kept in the correct orientation by means of a vane 20 - this reduces the effect of any current 19. |
