| 摘要 |
<p>A METHOD AND APPARATUS FOR TANK GAUGING USING DIODE LASERS AND OPTICAL FIBRES A method for determining the level of the surface of a material in a storage tank or vessel comprising the steps of modulating electrically an optical radiation beam by a radio frequency f, continuously variable over a suitable range, transmitting said beam to the surface of the material, receiving the beam reflected from said surface, adjusting the said frequency in order to obtain phase equality of the modulation in the measurement path in which the beam has travelled to the said surface and the modulation in a reference path in which the beam has not travelled to the said surface and deriving from this adjustment information as to the level in the tank or vessel. An apparatus for determining the level of the surface of a material in a storage tank or vessel comprising means for modulating electrically an optical radiation beam by a radio frequency f, continuously variable over a suitable range, means for transmitting said beam to the surface of the material, means for receiving the beam reflected from said surface, means for adjusting the said frequency in order to obtain phase equality of the modulation in the said measurement path in which the beam has travelled to the said surface and the modulation in a reference path, in which the beam has not travelled to the said surface and means for deriving from this adjustment information as to the level in the tank or vessel.</p> |
