| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved level sensor which is inexpensive, accurate, light in weight, and simple to use. SOLUTION: The sensor for determining the surface or interface level of a material comprises a transceiver (12) and an inner conductor (21) of a coaxial cable (16) for electrically coupling a guide wire (14) partially immersed in the material to the transceiver (12). A launcher plate (18) is connected to an outer shield (19) of the coaxial cable (16), and an impedance (20) connects the launcher plate (18) to the guide wire (14). The launcher plate (18) generates reference pulses transmitted back to the transceiver (12). Electromagnetic waves transmitted from the launcher plate (18) propagate along the guide wire (14). The electromagnetic waves are reflected by the surface or interface, received by the launcher plate (18), and therefrom, transmitted as reflection pulses to the transceiver (12). The transceiver (12) determines time delay between the reference and reflection pulses, and establishes the surface or interface level relative to the launcher plate (18). COPYRIGHT: (C)2004,JPO |
