Liquid-level gauging
AssigneeSmiths Industries Public Limited Company
InventorDavid Sinclair
Life of this patent
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Abstract
An ultrasonic liquid-level sensing system has a sensor with a number of reflectors mounted one above the other along the length of a tube that extends upwardly from a transducer and is filled with liquid to the same height as outside the tube. Liquid height is calculated from the difference between the arrival times of the pulses reflected from the two uppermost submerged reflectors and the difference between the arrival times of pulses reflected from the surface of the liquid and the uppermost submerged reflector.
Claims11
A liquid-level gauging system comprising:
- an ultrasonic liquid-level sensor, the sensor including an ultrasonic transducer mounted towards a lower end of the sensor and arranged to direct ultrasonic energy generally upwards through a liquid, at least three reflectors, and means mounting the at least three reflectors at known fixed positions and spacings one above the other along the entire height of the sensor such that each reflector submerged in liquid reflects ultrasound energy back to the transducer;
- and processing means operative to identify reflections from the uppermost two of the submerged reflectors, operative to derive information about the time of arrival of pulses, and operative to determine the height of the liquid above the uppermost one of the submerged reflectors from the times of arrival of pulses reflected from the liquid surface and the two uppermost submerged reflectors,
A method of liquid-level gauging including the steps of:
- energizing an ultrasound transducer submerged in liquid to produce bursts of ultrasound energy directed upwardly towards the liquid surface and toward a series of at least three reflectors mounted at known fixed positions and spacings one above the other along the entire length of an elongated sensor;
- receiving ultrasound energy reflected from the liquid surface and submerged ones of said reflectors;
- identifying reflections from the uppermost two of the submerged reflectors and the liquid surface, and calculating the height of liquid from the spacing of the reflectors and the times of arrival of pulses reflected from the liquid surface and the two uppermost submerged reflectors.
Dependencies are inferred from the claim text.