| 摘要 |
A liquid level sensing means for providing a continuous indication of liquid level or liquid content of a container comprising an elongated light conducting element adapted for being received into a liquid having first and second ends and a surface which provides an interface with the liquid for measuring liquid levels between the ends of the conducting element. A source provides radiation to the conducting element at one end, and detecting means for sensing radiation transmitted by the conducting element is positioned at the end of the conducting element opposite to the source of radiation and provides an output signal responsive to the intensity of the sensed radiation. The conducting element is transparent to radiation, has an index of refraction which is greater than that of the liquid which is to have its level measured, and has contoured regions on at least a portion of its surface. The contoured regions have an inclination which provides radiation impinging thereon from the source with an angle of incidence which is not greater that the critical angle characterizing the liquid interfaced regions, and which angle is greater than the critical angle characterizing regions which are not interfaced with the liquid, whereby the liquid interfaced regions refract radiation and the regions which are not interfaced with the liquid reflect radiation impinging thereon from the source, and the intensity of the radiation received by the detecting means is a function releated to the level of liquid between the ends of the conducting element.
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