| 摘要 |
Apparatus for detecting an interface (13) between two media of a heterogeneous system, comprising transmission means (21) to send a signal through one medium from the transmission means (21) to the interface (13), measuring means (32b, 32c, 32d) to measure the time taken for the signal to be reflected to a reception means (36), and processing means (40c, 40d) to use said time to determine the distance of the interface from the transmission means. |
