Leak-detection apparatus and liquid level variations detector

Claim 2

Liquid level variation detector, comprising in combination submerged means for transmitting acoustic energy into said liquid, signal-transducer means immersed in said liquid a variable amount depending upon the said liquid level, said transducer means having a geometric configuration for producing a resonant condition at a predetermined amount of immersion, and electric circuit means including said transducer means for indicating said liquid level variation.

Claim 3

Liquid level variation detector according to claim 1, wherein said submerged means and said signal transducer means each comprise a piezoelectric crystal.

Claim 4

Liquid level variation detector according to claim 2, wherein said transducer configuration is hollow cylindrical, and said submerged means is located coaxially with said transducer.

Claim 5

Liquid level variation detector according to claim 3, wherein said acoustic energy is ultrasonic.

Claim 6

Liquid level variation detector according to claim 4, further comprising an ultrasonic oscillator for driving said submerged crystal, and wherein said electric circuit means comprises an amplifier and means for measuring the amplitude of ultrasonic acoustic energy generated by said transducer crystal.

Claim 7

Liquid level variation detector according to claim 5, wherein the maximum of said variable immersion is about one-half wavelength of said driving oscillator frequency.

Claim 8

Liquid level variation detector for highly accurate measurements, comprising in combination a flat, cylindrical annular piezoelectric crystal submerged in said liquid with the axis thereof perpendicular to the surface of said liquid, an ultrasonic oscillator and circuit means for driving said flat crystal to generate acoustic energy having a predetermined ultrasonic frequency, said flat crystal being mounted on a lead base for absorbing downward-directed acoustic energy, a hollow, cylindrical piezoelectric crystal mounted coaxially with said flat crystal and immersed a variable amount in said liquid depending upon the said liquid level, said variable immersion having a maximum range equal to about one-half wavelength of said predetermined frequency, an amplifier connected to said hollow crystal, and a recorder for measuring the amplitude of said acoustic energy generated by said hollow crystal.

Claim 9

Liquid level variation detector for highly accurate measurements, comprising in combination a flat, cylindrical annular piezoelectric crystal submerged in said liquid with the axis thereof perpendicular to the surface of said liquid, an ultrasonic oscillator and circuit means for driving said flat crystal to generate acoustic energy having a predetermined ultrasonic frequency, said flat crystal being mounted on a lead base for absorbing downward-directed acoustic energy, a hollow, cylindrical piezoelectric crystal mounted coaxially with said flat crystal and immersed a variable amount in said liquid depending upon the said liquid level, said variable immersion having a maximum range equal to about one-half wavelength of said predetermined frequency, an amplifier connected to said hollow crystal, and a recorder for measuring the amplitude of said acoustic energy generated by said hollow crystal.

Claim 10

In leak detection of liquid contents from large tanks, apparatus for detecting a change in level of liquid in a relatively short time, comprising in combination, a housing having interior space for permitting said liquid therein, and a passageway near the bottom of said space for communicating with said large-tank liquid, valve means associated with said passageway for cutting off communication during said relatively short time, means for holding said housing partially submerged and fixed relative to the tank holding said liquid, and highly accurate liquid level-detecting means in said housing, comprising a submerged ultrasonic transmitter comprising a piezoelectric crystal, a partially immersed ultrasonic receiver comprising a piezoelectric crystal and having a geometric configuration for producing a resonant condition at a predetermined amount of immersion, and circuit means including said receiver for measuring the amplitude of ultrasonic signals generated by said receiver.

Claim 11

In leak detection of liquid contents from large tanks, apparatus for detecting a change in level of liquid in a relatively short time, comprising in combination, a housing having interior space for permitting said liquid therein, and a passageway near the bottom of said space for communicating with said large-tank liquid, valve means associated with said passageway for cutting off communication during said relatively short time, means for holding said housing partially submerged and fixed relative to the tank holding said liquid, and highly accurate liquid level-detecting means in said housing, comprising a submerged ultrasonic transmitter comprising a piezoelectric crystal, a partially immersed ultrasonic receiver comprising a piezoelectric crystal and having a geometric configuration for producing a resonant condition at a predetermined amount of immersion, and circuit means including said receiver for measuring the amplitude of ultrasonic signals generated by said receiver.

Claim 12

In leak detection, apparatus according to claim 8, wherein said receiver is hollow cylindrical shaped, and said transmitter is located coaxially with said receiver.

Claim 13

In leak detection, apparatus according to claim 9, wherein said transmitter has a flat cylindrical annular configuration.

Claim 14

In leak detection, apparatus according to claim 10, further comprising second circuit means for driving said transmitter at a predetermined ultrasonic frequency.

Claim 15

In leak detection, apparatus according to claim 11, wherein said transmitter frequency is fixed.

Claim 16

In leak detection of liquid contents from large tanks, apparatus for detecting a change in level of said liquid in a relatively short time, comprising in combination a housing having interior space for permitting said liquid therein and being constructed Of polytetrafluoroethylene, said housing including a passageway near the bottom of said space for communicating with said large-tank liquid, and vent means at the top of said space for equalizing ambient conditions with the atmosphere above said large-tank liquid, valve means associated with said passageway for cutting off communication during said relatively short time, means for suspending said housing at a fixed level partially submerged in said large-tank liquid, and highly accurate liquid level-detecting means in said housing comprising a submerged piezoelectric transmitter crystal having a flat cylindrical annular configuration, and mounted coaxially on a lead base with the axes thereof perpendicular to the surface of said liquid, a hollow cylindrical piezoelectric receiver crystal mounted coaxially with and above said submerged crystal, said last-named crystal having an outside diameter less than the inside diameter of said submerged crystal and being mounted for variable immersion in said liquid, an ultrasonic oscillator including circuit means for driving said transmitter crystal to generate acoustic energy having a predetermined ultrasonic frequency, and additional circuit means connected to said receiver crystal, including an amplifier and recording means for measuring the amplitude of ultrasonic signals generated by said receiver crystal.

Claim 17

In leak detection of liquid contents from large tanks, apparatus for detecting a change in level of said liquid in a relatively short time, comprising in combination a housing having interior space for permitting said liquid therein and being constructed Of polytetrafluoroethylene, said housing including a passageway near the bottom of said space for communicating with said large-tank liquid, and vent means at the top of said space for equalizing ambient conditions with the atmosphere above said large-tank liquid, valve means associated with said passageway for cutting off communication during said relatively short time, means for suspending said housing at a fixed level partially submerged in said large-tank liquid, and highly accurate liquid level-detecting means in said housing comprising a submerged piezoelectric transmitter crystal having a flat cylindrical annular configuration, and mounted coaxially on a lead base with the axes thereof perpendicular to the surface of said liquid, a hollow cylindrical piezoelectric receiver crystal mounted coaxially with and above said submerged crystal, said last-named crystal having an outside diameter less than the inside diameter of said submerged crystal and being mounted for variable immersion in said liquid, an ultrasonic oscillator including circuit means for driving said transmitter crystal to generate acoustic energy having a predetermined ultrasonic frequency, and additional circuit means connected to said receiver crystal, including an amplifier and recording means for measuring the amplitude of ultrasonic signals generated by said receiver crystal.