| 摘要 |
PCT No. PCT/SE90/00194 Sec. 371 Date Dec. 4, 1990 Sec. 102(e) Date Dec. 4, 1990 PCT Filed Mar. 27, 1990 PCT Pub. No. WO90/12292 PCT Pub. Date Oct. 18, 1990.A device for gauging the level of a fluid in a container having a gas above the surface of the fluid. The device comprises a microwave transmitter transmitting a microwave radio signal through the gas to the surface and a receiver for receiving the microwave signal reflected by the surface. An electronic unit is arranged to calculate from the propagation time of the microwave signal a first distance from the transmitter to the surface of the fluid and thereby the level in the container. The microwave signal is preferably within the radar frequency range. A sound transmitter is also provided for transmitting a sound signal through the gas to the surface of the fluid and is capable of receiving a sound signal reflected from the surface of the fluid. A means is provided for correcting the first distance to a second corrected distance as a function of the microwave velocity and the known relation between the sound velocity and the microwave velocity.
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