Ultrasonic profile measuring apparatus

Claim 2

Apparatus for measuring variations in ultrasonic transmission characteristics in a medium over a series of discrete intervals along a predetermined path as indicative of the value over a range of values of an ambient condition affecting ultrasonic transmission characteristics comprising, a transducer for generating ultrasonic waves and for generating output electrical signals in response to received ultrasonic waves, a series of at least three sensor elements formed by ultrasonic discontinuities spaced at discrete equal intervals along said path, the acoustic impedances of said discontinuities being substantially identical and of a relative value such that the acoustic reflection coefficient for each discontinuity for ultrasonic waves traveling in a first direction is no greater than 0.1 over said range of values of said ambient condition; and said transducer being positioned to transmit generated ultrasonic waves along said path and to receive ultrasonic waves reflected from said sensor elements and provide an output signal indicative of the time separation between reflections from successive ones of said reflection elements.

Claim 3

Apparatus in accordance with claim 1 wherein said reflection elements are formed of ultrasonic discontinuities in a solid cylindrical member extending along said path, said cylindrical member having a diameter substantially less than the wavelength of said generated ultrasonic waves, said transducer being coupled to one end of said solid cylindrical member.

Claim 4

Apparatus in accordance with claim 2 wherein said ultrasonic discontinuities are formed of changes in diameter of said solid cylindrical member.

Claim 5

Apparatus in accordance with claim 2 wherein said solid cylindrical member is of substantially constant diameter.

Claim 6

Apparatus in accordance with claim 4 wherein said solid cylindrical member is formed of equal length segments of alternately first and second material, the acoustic properties of each of said first and second mateRials being such as to provide at each material interface reflection coefficients no greater than 0.10.

Claim 7

Apparatus in accordance with claim 5 wherein said first material is tungsten and said second material is rhenium.

Claim 8

Apparatus in accordance with claim 4 wherein each discontinuity is formed of a bend in said element of radius approximately equal to the wavelength of said generated ultrasonic waves.

Claim 9

Apparatus in accordance with claim 3 wherein said transducer is positioned between two of said sensor elements, said ultrasonic discontinuities being arranged such that the reflection coefficient of any of said discontinuities in sensors on one side of said transducer has the opposite polarity from the reflection coefficient of discontinuities in sensors on the opposite side of said transducer.

Claim 10

Apparatus in accordance with claim 8 wherein said sensors are formed of a series of cylindrical elements, the diameter of each cylindrical element in said series being smaller than the diameter of the preceding element in said series.

Claim 11

Apparatus for measuring variations in ultrasonic transmission characteristics in a fluid medium over a series of discrete intervals along a predetermined path as indicative of the value over a range of values of an ambient condition affecting ultrasonic transmission characteristics, a transducer for emitting a beam of ultrasonic waves along said predetermined path and for producing in response to received ultrasonic waves output electric signals; a series of at least three reflection elements spaced at discrete equal intervals along said path within said fluid medium, each of said reflection elements being formed to reflect a portion of said ultrasonic beam back toward said transducer, the effective reflection coefficient for each of said reflection elements being substantially the same and less than 0.10; and means responsive to the electrical signals produced by said transducer to provide output signals indicative of the time separation between reflections from successive ones of said reflection elements as indicative of the ultrasonic transmission characteristics in each of said series of discrete intervals.

Claim 12

Apparatus for measuring variations in ultrasonic transmission characteristics in a fluid medium over a series of discrete intervals along a predetermined path as indicative of the value over a range of values of an ambient condition affecting ultrasonic transmission characteristics, a transducer for emitting a beam of ultrasonic waves along said predetermined path and for producing in response to received ultrasonic waves output electric signals; a series of at least three reflection elements spaced at discrete equal intervals along said path within said fluid medium, each of said reflection elements being formed to reflect a portion of said ultrasonic beam back toward said transducer, the effective reflection coefficient for each of said reflection elements being substantially the same and less than 0.10; and means responsive to the electrical signals produced by said transducer to provide output signals indicative of the time separation between reflections from successive ones of said reflection elements as indicative of the ultrasonic transmission characteristics in each of said series of discrete intervals.

Claim 13

Apparatus in accordance with claim 10 wherein each of said reflection elements are independent from one another.

Claim 14

Apparatus in accordance with claim 10 wherein each of said reflection elements are substantially identical in form and composition.

Claim 15

Apparatus in accordance with claim 10 wherein said reflection elements are formed of a series of solid reflection surfaces, each of said surfaces extending normal to said path and transverse of said ultrasonic beam, each of said solid reflection surfaces being interconnected to form a stepped element, the total dimension of said stepped element in a direction transverse of said ultrasonic beam being less than the cross-sectional dimension of said ultrasonic beam.

Claim 16

Apparatus in accordance with claim 11 wherein each of said elements is formed of a polyester film, the thickness of said polyester film being substantially less than one-fourth the wavelength characteristic of said emitted ultrasonic beam.

Claim 17

Apparatus in accordance with claim 11 wherein each of said reflection elements is formed of a mesh screen.

Claim 18

Apparatus in accordance with claim 11 wherein each of said reflection elements is formed of a plate member extending in a direction transverse of said ultrasonic beam, each of said plate members being formed with an opening therethrough, the openings in successive ones of said plates being such as to reflect substantially the same proportion of ultrasonic waves incident thereon to provide said substantially uniform pulse heights at said transducer from ultrasonic waves reflected from each of said plates.

Claim 19

Apparatus in accordance with claim 16 wherein the openings in successive ones of said plates are successively smaller.

Claim 20

Apparatus as in claim 10 wherein each of said elements is formed of a thin metal plate, the Thickness of the plate in fractional wavelength being less than the ratio of the characteristic impedance of the fluid to that of the plate.

Claim 21

Apparatus for measuring variations in ultrasonic transmission characteristics as in a flowing fluid medium over a series of discrete intervals along a predetermined path normal to the direction of flow as indicative of the velocity of flow and the value of another ambient condition affecting the ultrasonic transmission characteristics comprising, a first transducer for emitting a first beam of ultrasonic waves in a first direction along said predetermined path, and for providing output electrical signals in response to received ultrasonic waves, a series of at least three reflection elements spaced at said discrete intervals along said said path, each of said reflection elements being formed to reflect a portion of said beam in a direction parallel to the direction of flow of said fluid, the effective reflection coefficient for each of said reflection elements being less than 0.10, a plurality of second transducer means positioned to receive the ultrasonic waves from said first beam reflected from said reflection elements and provide output electrical signals in response thereto, said second transducers emitting a plurality of ultrasonic beams in a second direction opposite to said first direction to strike each of said reflection elements and be reflected back to said first transducer, and means responsive to said output electrical signals to provide for each of said discrete intervals an indication of the ultrasonic transmission characteristics and of the flow velocity.

Claim 22

Apparatus for measuring variations in ultrasonic transmission characteristics as in a flowing fluid medium over a series of discrete intervals along a predetermined path normal to the direction of flow as indicative of the velocity of flow and the value of another ambient condition affecting the ultrasonic transmission characteristics comprising, a first transducer for emitting a first beam of ultrasonic waves in a first direction along said predetermined path, and for providing output electrical signals in response to received ultrasonic waves, a series of at least three reflection elements spaced at said discrete intervals along said said path, each of said reflection elements being formed to reflect a portion of said beam in a direction parallel to the direction of flow of said fluid, the effective reflection coefficient for each of said reflection elements being less than 0.10, a plurality of second transducer means positioned to receive the ultrasonic waves from said first beam reflected from said reflection elements and provide output electrical signals in response thereto, said second transducers emitting a plurality of ultrasonic beams in a second direction opposite to said first direction to strike each of said reflection elements and be reflected back to said first transducer, and means responsive to said output electrical signals to provide for each of said discrete intervals an indication of the ultrasonic transmission characteristics and of the flow velocity.