| 摘要 |
<p>An apparatus is disclosed for detecting small changes in the level of liquid (21) in a storage tank (20). The apparatus comprises a float means (38) floating at a desired depth (x) in the liquid (21). The float means (38) has a reservoir for holding a liquid measuring medium (19) and is movably connected to a support means (28). The support means (28) carries a source (32) for emitting electromagnetic radiation, e.g. light, and a detector means (36) arranged within the reservoir. The intensity of the radiation received by the detector means (36) is modulated according to changes in the location of the float means (38), i.e. according to changes in the level of liquid (21) in the storage tank (20). A method using this apparatus is disclosed for detecting leaks in liquid storage tanks by monitoring the signal representing the location of the float means.</p> |
