Ultrasonic testing system
First Claim
1. In an ultrasonic pulse-echo instrument for detection of defects in a solid part, transducer means, transmitting and receiving means for energizing said transducer means to transmit a burst of ultrasonic energy into the part and for developing echo signals in response to reflections from defects within the part, said transducer means being arranged for back and forth movement toward and away from a defect to obtain a variable length wave transmission path between said transducer means and the defect, doppler circuit means coupled to said transmitting and receiving means for responding to changes in the timing of said echo signals relative to the transmitted bursts and for developing a doppler signal at an audible frequency proportional to the rate of change in the effective length of said variable length wave transmission path, and means for applying said doppler signal to electro-acoustical transducer means to produce an audible signal in response to said movement of said transducer means toward and away from the defect.
1 Assignment
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Accused Products
Abstract
An ultrasonic system for detection of defects is provided including a pulse-echo instrument having a cathode ray tube on which an A-scan visual indication of flaws is produced and including a doppler circuit arranged to produce a doppler signal in an audible range in response to movement of a transducer relative to defects in a pipe seam or other region being investigated. The doppler signal is applied to earphones, permitting the existence of defects to be reliably determined audibly, after which the defects may be more carefully studied through the visual indications on the cathode ray tube. The doppler signal is also recorded on one track of a magnetic tape with operator'"'"'s comments being recorded on a second track of the same tape. The doppler circuit includes an oscillator operated during a gating time interval to generate a reference signal, a phase detector responsive to a reference signal and to echo ignals, and a sample and hold circuit for storing the output of the phase detector from one cycle to the next.
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Citations
10 Claims
- 1. In an ultrasonic pulse-echo instrument for detection of defects in a solid part, transducer means, transmitting and receiving means for energizing said transducer means to transmit a burst of ultrasonic energy into the part and for developing echo signals in response to reflections from defects within the part, said transducer means being arranged for back and forth movement toward and away from a defect to obtain a variable length wave transmission path between said transducer means and the defect, doppler circuit means coupled to said transmitting and receiving means for responding to changes in the timing of said echo signals relative to the transmitted bursts and for developing a doppler signal at an audible frequency proportional to the rate of change in the effective length of said variable length wave transmission path, and means for applying said doppler signal to electro-acoustical transducer means to produce an audible signal in response to said movement of said transducer means toward and away from the defect.
Specification