Ultrasonic nondestructive material tester

Claim 2

A search unit for testing a workpiece including the combination of a housing adapted to be placed in intimate contact with the workpiece, transducer means in said housing for transmitting ultrasonic energy, and a fluid couplant in said housing for acoustically coupling the transducer means to the workpiece, said transducer means being constructed and arranged to transmit and receive ultrasonic energy at a first and relatively high testing frequency in which the workpiece is inspected for discontinuities therein and to transmit ultrasonic energy at a second and relatively lower frequency selected particularly for and being effective to agitate said fluid couplant so as to condition said couplant for effective transmission and reception of ultrasonic energy at said testing frequency.

Claim 3

The search unit of claim 1 wherein the transducer means includes a first transducer for transmitting the ultrasonic energy at said first frequency, and a second transducer for transmitting the ultrasonic energy at said second frequency.

Claim 4

A search unit for testing a workpiece including the combination of a housing, a liquid couplant in said housing, a first transducer means disposed in said housing and communicating with the couplant for radiating ultrasonic energy through said couplant and into the workpiece and for receiving reflected ultrasonic energy from such workpiece, said energy having a first relatively high frequency effEctive to penetrate into the workpiece and reflect from discontinuities therein, and a second transducer means disposed in said housing and communicating with the couplant for radiating ultrasonic energy through said couplant, the energy radiated by said second transducer means having a second frequency lower than said first relatively high frequency, said second frequency selected particularly for and only for agitating said liquid couplant.

Claim 5

A search unit for testing a workpiece including the combination of a housing, a liquid couplant in said housing, a first transducer means disposed in said housing and communicating with the couplant for radiating ultrasonic energy through said couplant and into the workpiece and for receiving reflected ultrasonic energy from such workpiece, said energy having a first relatively high frequency effEctive to penetrate into the workpiece and reflect from discontinuities therein, and a second transducer means disposed in said housing and communicating with the couplant for radiating ultrasonic energy through said couplant, the energy radiated by said second transducer means having a second frequency lower than said first relatively high frequency, said second frequency selected particularly for and only for agitating said liquid couplant.

Claim 6

The search unit of claim 3 wherein the first transducer means is disposed in the center of said housing, and the second transducer means is disposed concentric about the first transducer.

Claim 7

A nondestructive testing system for inspecting workpieces, said system including the combination of an ultrasonic search unit adapted to be acoustically coupled to the workpiece, a first transducer in said search unit for transmitting ultrasonic energy, a second transducer in said search unit for transmitting ultrasonic energy, a liquid couplant in said search unit acoustically coupling said first and second transducers to the workpiece, first transmitting means for providing a first electrical signal, said first transmitting means being coupled to said first transducer for energizing said transducer whereby said first transducer transmits ultrasonic energy through the couplant and into the workpiece such that echoes of the ultrasonic energy are reflected from within the workpiece back to the first transducer, said first electrical signal effective to energize said first transducer at a relatively high testing frequency, a receiver coupled to the first transducer for receiving the signal produced by said first transducer as a result of said echoes, and second transmitting means for providing a second electrical signal, said second transmitting means being coupled to the second transducer to energize such transducer to transmit ultrasonic energy through the couplant to the workpiece, said second electrical signal being selected to cause said second transducer to transmit ultrasonic energy of a frequency and magnitude sufficient to agitate the couplant adjacent the face.

Claim 8

A nondestructive testing system for inspecting workpieces, said system including the combination of an ultrasonic search unit adapted to be acoustically coupled to the workpiece, a first transducer in said search unit for transmitting ultrasonic energy, a second transducer in said search unit for transmitting ultrasonic energy, a liquid couplant in said search unit acoustically coupling said first and second transducers to the workpiece, first transmitting means for providing a first electrical signal, said first transmitting means being coupled to said first transducer for energizing said transducer whereby said first transducer transmits ultrasonic energy through the couplant and into the workpiece such that echoes of the ultrasonic energy are reflected from within the workpiece back to the first transducer, said first electrical signal effective to energize said first transducer at a relatively high testing frequency, a receiver coupled to the first transducer for receiving the signal produced by said first transducer as a result of said echoes, and second transmitting means for providing a second electrical signal, said second transmitting means being coupled to the second transducer to energize such transducer to transmit ultrasonic energy through the couplant to the workpiece, said second electrical signal being selected to cause said second transducer to transmit ultrasonic energy of a frequency and magnitude sufficient to agitate the couplant adjacent the face.

Claim 9

A nondestructive testing system for inspecting hot workpieces, said system including the combination of an ultrasonic search unit adapted to be coupled to the workpiece, a liquid couplant in said search unit in intimate contact with the workpiece, a first transducer in said search unit immersed in said couplant for transmitting ultrasonic energy through said couplant and into the workpiece in response to an electrical signal and for generating an electrical signal in response to ultrasonic energy which returns from the workpiece and passes through said couplant so as to be incident upon said first transducer, first means coupled to said first transducer for providing an electrical signal effective to cause said first transducer to transmit said ultrasonic energy at a relatively high inspection frequency, and second means coupled to the second transducer for providing a second electrical signal effective to cause the second transducer to transmit ultrasonic energy at a liquid agitating frequency which is lower than said inspection frequency whereby the liquid couplant in said search unit is agitated to minimize the presence of bubbles in said couplant adjacent the workpiece wherein such bubbles otherwise interfere with the transmission of ultrasonic energy at said inspection frequency.

Claim 10

A nondestructive testing system for inspecting hot workpieces, said system including the combination of an ultrasonic search unit adapted to be coupled to the workpiece, a liquid couplant in said search unit in intimate contact with the workpiece, a first transducer in said search unit immersed in said couplant for transmitting ultrasonic energy through said couplant and into the workpiece in response to an electrical signal and for generating an electrical signal in response to ultrasonic energy which returns from the workpiece and passes through said couplant so as to be incident upon said first transducer, first means coupled to said first transducer for providing an electrical signal effective to cause said first transducer to transmit said ultrasonic energy at a relatively high inspection frequency, and second means coupled to the second transducer for providing a second electrical signal effective to cause the second transducer to transmit ultrasonic energy at a liquid agitating frequency which is lower than said inspection frequency whereby the liquid couplant in said search unit is agitated to minimize the presence of bubbles in said couplant adjacent the workpiece wherein such bubbles otherwise interfere with the transmission of ultrasonic energy at said inspection frequency.

Claim 11

The nondestructive testing system of claim 6 wherein the second means includes an oscillator.

Claim 14

The method as defined in claim 8 further comprising: applying an electrical signal to the second transducer from an oscillator having a frequency selected to energize the second transducer at said relatively low liquid agitating frequency.

Claim 15

The method of claim 8 further comprising: focusing the relatively low frequency ultrasonic energy from the second transducer to agitate the liquid couplant adjacent an area of the workpiece at which ultrasonic energy at the relatively high testing frequency from said first transducer enters the workpiece.