Pulse-echo gauging system

Claim 2

IN A SYSTEM FOR ECHO RANGING FROM A REFERENCE REGION TO A LIQUID SURFACE, FIRST AND SECOND ELONGATED TUBULAR CONDUCTORS OF ELASTIC WAVE ENERGY DISPOSED TO EXTEND FROM SAID REFERENCE REGION THROUGH SAID SURFACE, MEANS ACOUSTICALLY COUPLED TO SAID FIRST CONDUCTOR TO ESTABLISH ELASTIC WAVE VIBRATIONS THEREIN IN A RADIAL MODE HAVING AXIAL SYMMETRY AND PROPAGATING AXIALLY ALONG SAID CONDUCTOR BETWEEN SAID REFERENCE POINT AND SAID SURFACE, AND ELECTROMECHANICAL TRANSDUCER MEANS ACOUSTICALLY COUPLED TO SAID SECOND CONDUCTOR ADAPTED TO RESPOND TO SIMILAR VIBRATIONS PROPAGATING IN SAID SECOND CONDUCTOR, THE RATIO T/D BETWEEN THE MAXIMUM WALL THICKNESS "T" AND THE MEAN DIAMETER "D" OF EACH CONDUCTOR BEING OF THE ORDER OF 5 PERCENT.

Claim 3

IN COMBINATION, A CONTAINER FOR A LIQUID, SAID CONTAINER HAVING A HORIZONTAL CROSS SECTION WHICH IS NONUNIFORM WITH RESPECT TO VERTICAL POSITION IN SAID CONTAINER, AN ELONGATED TUBULAR CONDUCTOR OF ELASTIC WAVE ENERGY DISPOSED TO EXTEND FROM A REFERENCE POINT SUBSTANTIALLY VERTICALLY TO A REGION NEAR THE BOTTOM OF SAID CONTAINER, AND MEANS ACOUSTICALLY COUPLED TO SAID CONDUCTOR TO ESTABLISH ELASTIC WAVE VIBRATIONS THEREIN IN A RADIAL MODE HAVING AXIAL SYMMETRY AND PROPAGATING AXIALLY ALONG SAID CONDUCTOR BETWEEN SAID REFERENCE POINT AND SAID REGION, THE RATIO T/D BETWEEN THE MAXIMUM WALL THICKNESS "T" AND THE MEAN DIAMETER "D" OF SAID CONDUCTOR BEING OF THE ORDER OF 5 PERCENT, THE WALL THICKNESS "T" OF SAID CONDUCTOR BEING VARIED WITH RESPECT TO AXIAL POSITION THEREIN TO PROVIDE THINNER CONDUCTOR WALL SECTIONS IN REGIONS OF LARGER HORIZONTAL CROSS SECTION OF SAID CONTAINER SO THAT EQUAL TIMES OF PROPAGATION OF SAID WAVES THEREIN WILL CORRESPOND TO EQUAL CROSS-SECTIONAL VOLUMES OF SAID CONTAINER.

Claim 4

IN COMBINATION, A CONTAINER FOR A LIQUID, SAID CONTAINER HAVING A HORIZONTAL CROSS SECTION WHICH IS NONUNIFORM WITH RESPECT TO VERTICAL POSITION IN SAID CONTAINER, AN ELONGATED TUBULAR CONDUCTOR OF ELASTIC WAVE ENERGY DISPOSED TO EXTEND FROM A REFERENCE POINT SUBSTANTIALLY VERTICALLY TO A REGION NEAR THE BOTTOM OF SAID CONTAINER, AND MEANS ACOUSTICALLY COUPLED TO SAID CONDUCTOR TO ESTABLISH ELASTIC WAVE VIBRATIONS THEREIN IN A RADIAL MODE HAVING AXIAL SYMMETRY AND PROPAGATING AXIALLY ALONG SAID CONDUCTOR BETWEEN SAID REFERENCE POINT AND SAID REGION, THE RATIO T/D BETWEEN THE MAXIMUM WALL THICKNESS "T" AND THE MEAN DIAMETER "D" OF SAID CONDUCTOR BEING OF THE ORDER OF 5 PERCENT, THE WALL THICKNESS "T" OF SAID CONDUCTOR BEING VARIED WITH RESPECT TO AXIAL POSITION THEREIN TO PROVIDE THINNER CONDUCTOR WALL SECTIONS IN REGIONS OF LARGER HORIZONTAL CROSS SECTION OF SAID CONTAINER SO THAT EQUAL TIMES OF PROPAGATION OF SAID WAVES THEREIN WILL CORRESPOND TO EQUAL CROSS-SECTIONAL VOLUMES OF SAID CONTAINER.