Ultrasonic inspection apparatus

Claim 2

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, transmitting search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of ultrasonic energy into the workpiece, receiving search unit means effective to receive said burst of energy from said workpiece, said receiving search unit means being effective to produce a multicycle signal corresponding to said burst and having a time duration corresponding to the duration of said burst, a receiver coupled to said receiving search unit means and responsive to the signal therefrom to produce a multicycle received signal, and means in said receiver coupled to the transmitter, said last means being responsive to said received signal at a predetermined reference time after said driving signal for a predetermined sample time shorter than the duration of said burst and effective to produce an output signal which is a function of the variations in the instantaneous value of said received signal.

Claim 3

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, transmitting search unit means coupled to said transmitter and responsive to the driving signal from said transmitter and effective to transmit ultrasonic energy into said workpiece, receiving search unit means effective to receive said energy from said workpiece and to produce a signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received signal, first sampling means in said receiver and coupled to said transmitter, said first sampling means being responsive to said driving signal and effective at a first predetermined reference time after said driving signal to sample said received signal and provide a first sample signal that is a function of said received signal at said first reference time, and second sampling means in said receiver and coupled to said transmitter, said second sampling means being responsive to said driving signal and effective at a second predetermined reference time after said driving signal to sample said received signal and provide a second sample signal that is a function of the received signal at said second rEference time.

Claim 4

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, transmitting search unit means coupled to said transmitter and responsive to the driving signal from said transmitter and effective to transmit ultrasonic energy into said workpiece, receiving search unit means effective to receive said energy from said workpiece and to produce a signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received signal, first sampling means in said receiver and coupled to said transmitter, said first sampling means being responsive to said driving signal and effective at a first predetermined reference time after said driving signal to sample said received signal and provide a first sample signal that is a function of said received signal at said first reference time, and second sampling means in said receiver and coupled to said transmitter, said second sampling means being responsive to said driving signal and effective at a second predetermined reference time after said driving signal to sample said received signal and provide a second sample signal that is a function of the received signal at said second rEference time.

Claim 5

The material tester of claim 2 including a cathode ray tube having first deflection means coupled to the first sampling means and second deflection means coupled to the second sampling means.

Claim 6

The material tester of claim 2 including timing means coupled to said transmitter and responsive to said driving signal, said timing means being coupled to said first and second sampling means.

Claim 7

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting ultrasonic energy into the workpiece, receiving search unit means for receiving said ultrasonic energy from the workpiece and effective to produce a signal corresponding to the received ultrasonic energy, a transmitter coupled to the transmitting search unit means for energizing the search unit means whereby said ultrasonic energy is transmitted into the workpiece and a signal is produced by the receiving search unit means corresponding to the received energy, a receiver coupled to the receiving search unit means for receiving said signal, and sampling means in said receiver coupled to the transmitter and effective to sample the received signal at a particular reference time after the transmission of said ultrasonic energy to produce a signal which is a function of the received signal at said predetermined reference time.

Claim 8

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting ultrasonic energy into the workpiece, receiving search unit means for receiving said ultrasonic energy from the workpiece and effective to produce a signal corresponding to the received ultrasonic energy, a transmitter coupled to the transmitting search unit means for energizing the search unit means whereby said ultrasonic energy is transmitted into the workpiece and a signal is produced by the receiving search unit means corresponding to the received energy, a receiver coupled to the receiving search unit means for receiving said signal, and sampling means in said receiver coupled to the transmitter and effective to sample the received signal at a particular reference time after the transmission of said ultrasonic energy to produce a signal which is a function of the received signal at said predetermined reference time.

Claim 9

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting ultrasonic energy into the workpiece, receiving search unit means for receiving said ultrasonic energy from said workpiece and being effective to produce a signal corresponding to the received ultrasonic energy, a transmitter coupled to the transmitting search unit means fo energizing the search unit means whereby said ultrasonic energy is transmitted into the workpiece and the signal produced by the receiving search unit means corresponds to the characteristics of the workpiece, a receiver coupled to the receiving search unit means for receiving the signal therefrom, a first channel in said receiver, said channel including first time delay means coupled to the transmitter and first sampling means, said first sampling means being effective to sample the received signal at a first particular reference time determined by said time delay means to produce a first sample signal which is a function of the received signal at said first predetermined reference time, and a second channel in said receiver, said second channel including second time delay means coupled to the transmitter and second sampling means, said second sampling means being effective to sample the received signal at a second particular reference time determined by said second delay means to produce a second reference signal which is a function of the received signal at said second predetermined reference time.

Claim 10

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting ultrasonic energy into the workpiece, receiving search unit means for receiving said ultrasonic energy from said workpiece and being effective to produce a signal corresponding to the received ultrasonic energy, a transmitter coupled to the transmitting search unit means fo energizing the search unit means whereby said ultrasonic energy is transmitted into the workpiece and the signal produced by the receiving search unit means corresponds to the characteristics of the workpiece, a receiver coupled to the receiving search unit means for receiving the signal therefrom, a first channel in said receiver, said channel including first time delay means coupled to the transmitter and first sampling means, said first sampling means being effective to sample the received signal at a first particular reference time determined by said time delay means to produce a first sample signal which is a function of the received signal at said first predetermined reference time, and a second channel in said receiver, said second channel including second time delay means coupled to the transmitter and second sampling means, said second sampling means being effective to sample the received signal at a second particular reference time determined by said second delay means to produce a second reference signal which is a function of the received signal at said second predetermined reference time.

Claim 11

The material tester of claim 6 including a cathode ray tube having first deflection means coupled to the first channel and second deflection means coupled to the second channel.

Claim 12

A material tester including the combination of a first ultrasonic search unit, a transmitter coupled to said first search unit, a second ultrasonic search unit, a receiver coupled to said second search unit means, first signal sampling means in said receiver, second signal sampling means in said receiver, first timing means coupled to said transmitter and to said first signal sampling means, second timing means coupled to said transmitter and to said second signal sampling means, and a cathode ray tube coupled to the first and second signal sampling means.

Claim 13

A material tester including the combination of a first ultrasonic search unit, a transmitter coupled to said first search unit, a second ultrasonic search unit, a receiver coupled to said second search unit means, first signal sampling means in said receiver, second signal sampling means in said receiver, first timing means coupled to said transmitter and to said first signal sampling means, second timing means coupled to said transmitter and to said second signal sampling means, and a cathode ray tube coupled to the first and second signal sampling means.

Claim 14

The material tester of claim 8 including a transmit transducer in the first search unit coupled to the transmitter for transmitting ultrasonic energy, and a receiver transducer in the second search unit coupled to the receiver For receiving ultrasonic energy.

Claim 15

The material tester of claim 8 wherein said first and second signal sampling means include sample and hold circuits.

Claim 16

A material tester including the combination of a first ultrasonic search unit, a transmitter coupled to said first search unit, a second ultrasonic search unit, a receiver coupled to said second search unit, a first channel in said receiver, first signal sampling means in said first channel coupled to the second search unit, first timing means in said first channel coupled to the transmitter and to the first signal sampling means, a second channel in said receiver parallel to the first channel and coupled to the second search unit, second signal sampling means in said first channel coupled to the second search unit, second timing means in said second channel coupled to the transmitter and to the second signal sampling means, and a cathode ray tube having first deflection means coupled to the first channels and second deflection means coupled to the first channels and second deflection means coupled to the second channel.

Claim 17

A material tester including the combination of a first ultrasonic search unit, a transmitter coupled to said first search unit, a second ultrasonic search unit, a receiver coupled to said second search unit, a first channel in said receiver, first signal sampling means in said first channel coupled to the second search unit, first timing means in said first channel coupled to the transmitter and to the first signal sampling means, a second channel in said receiver parallel to the first channel and coupled to the second search unit, second signal sampling means in said first channel coupled to the second search unit, second timing means in said second channel coupled to the transmitter and to the second signal sampling means, and a cathode ray tube having first deflection means coupled to the first channels and second deflection means coupled to the first channels and second deflection means coupled to the second channel.

Claim 18

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle burst of energy into the workpiece and receiving said energy from said workpiece, said search unit means being effective to produce a received signal corresponding to the energy received from said workpiece, and means coupled to said search unit means and responsive to the transmission of said burst of energy and effective to define a reference interval which occurs a predetermined time after said transmission and has a time duration shorter than the duration of said burst, said last means being responsive to the magnitude of said received signal during said reference interval.

Claim 19

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle burst of energy into the workpiece and receiving said energy from said workpiece, said search unit means being effective to produce a received signal corresponding to the energy received from said workpiece, and means coupled to said search unit means and responsive to the transmission of said burst of energy and effective to define a reference interval which occurs a predetermined time after said transmission and has a time duration shorter than the duration of said burst, said last means being responsive to the magnitude of said received signal during said reference interval.

Claim 20

The material tester of claim 12 including sampling means in said last means for sampling the received signal during said reference interval to produce an output signal, said output signal being a function of the magnitude of the received signal during said interval.

Claim 21

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of energy into the workpiece, said search unit means being effective to receive said energy from said workpiece and produce a multicycle signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received multicycle signal having a time duration corresponding to the time duration of said transmitted burst of energy, and sampling means in said receiver effective to sample said received signal during a sample interval to produce an output signal which is a function of the received signal during said sample interval, said sampling means being responsive to said driving signal whereby the sample interval is delayed a predetermined time from said transmitted burst and is shorter than said burst.

Claim 22

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of energy into the workpiece, said search unit means being effective to receive said energy from said workpiece and produce a multicycle signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received multicycle signal having a time duration corresponding to the time duration of said transmitted burst of energy, and sampling means in said receiver effective to sample said received signal during a sample interval to produce an output signal which is a function of the received signal during said sample interval, said sampling means being responsive to said driving signal whereby the sample interval is delayed a predetermined time from said transmitted burst and is shorter than said burst.

Claim 23

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of energy into the workpiece, said search unit means being effective to receive said energy from said workpiece and produce a multicycle signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received multicycle signal having a time duration corresponding to the time duration of said transmitted burst of energy, sampling means having a sample interval which is shorter than said burst and said received signal, said sample means being coupled to said receiver to sample said received signal during said sample interval to produce an output signal which is a function of the received signal during said sample interval, and time delay means coupled to said transmitter and said sampling means, said time delay means being responsive to said driving signal and effective to actuate said sampling means whereby the sample interval is delayed a predetermined time from said transmitted burst.

Claim 24

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of energy into the workpiece, said search unit means being effective to receive said energy from said workpiece and produce a multicycle signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received multicycle signal having a time duration corresponding to the time duration of said transmitted burst of energy, sampling means having a sample interval which is shorter than said burst and said received signal, said sample means being coupled to said receiver to sample said received signal during said sample interval to produce an output signal which is a function of the received signal during said sample interval, and time delay means coupled to said transmitter and said sampling means, said time delay means being responsive to said driving signal and effective to actuate said sampling means whereby the sample interval is delayed a predetermined time from said transmitted burst.

Claim 25

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to the driving signal from transmitter and effective to transmit a multicycle burst of ultrasonic energy into said workpiece, said search unit means being effective to receive said energy from said workpiece and to produce a signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received signal, first sampling means in said receiver for sampling said received signal during a first predetermined sample interval to produce a first sample signal that is a function of the received signal during said first sample interval, and second sampling means in said receiver for sampling said recieved signal during a second predetermined sample interval to provide a second sample that is a function of the received signal during said second sample interval, and time delay means coupled to said transmitter and responsive to said driving signal, said time delay means being coupled to said first and second sampling means whereby said first and second sample intervals are delayed from the driving signal by predetermined amounts and the sample intervals have durations which are shorter than the duration of said transmitted burst.

Claim 26

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, search unit means coupled to said transmitter and responsive to the driving signal from transmitter and effective to transmit a multicycle burst of ultrasonic energy into said workpiece, said search unit means being effective to receive said energy from said workpiece and to produce a signal corresponding thereto, a receiver coupled to said search unit means and responsive to the signal therefrom to produce a received signal, first sampling means in said receiver for sampling said received signal during a first predetermined sample interval to produce a first sample signal that is a function of the received signal during said first sample interval, and second sampling means in said receiver for sampling said recieved signal during a second predetermined sample interval to provide a second sample that is a function of the received signal during said second sample interval, and time delay means coupled to said transmitter and responsive to said driving signal, said time delay means being coupled to said first and second sampling means whereby said first and second sample intervals are delayed from the driving signal by predetermined amounts and the sample intervals have durations which are shorter than the duration of said transmitted burst.

Claim 27

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle pulse of energy having a predetermined time duration into the workpiece search unit means being effective to receive said energy from said workpiece and produce a multicycle electrical signal having a time displacement and duration corresponding to the time displacement and duration of the energy, a transmitter coupled to the search unit means for energizing the search unit means for said predetermined time duration whereby said energy is transmitted into the workpiece and said multicycle electrical signal is produced by the search unit means corresponding to the received energy, a receiver coupled to the search unit means for receiving said multicycle electrical signal, and sampling means in said receiver and coupled to said transmitter to be responsive to the transmission of said pulse, said sampling means being effective to sample said electrical signal a predetermined time after said transmission and during a time interval which is shorter than said predetermined time duration to produce a signal which is a function of the time displacement of said received signal.

Claim 28

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle pulse of energy having a predetermined time duration into the workpiece search unit means being effective to receive said energy from said workpiece and produce a multicycle electrical signal having a time displacement and duration corresponding to the time displacement and duration of the energy, a transmitter coupled to the search unit means for energizing the search unit means for said predetermined time duration whereby said energy is transmitted into the workpiece and said multicycle electrical signal is produced by the search unit means corresponding to the received energy, a receiver coupled to the search unit means for receiving said multicycle electrical signal, and sampling means in said receiver and coupled to said transmitter to be responsive to the transmission of said pulse, said sampling means being effective to sample said electrical signal a predetermined time after said transmission and during a time interval which is shorter than said predetermined time duration to produce a signal which is a function of the time displacement of said received signal.

Claim 29

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting a multicycle burst of ultrasonic energy into the workpiece, receiving search unit means for receiving said energy from said workpiece, said receiving search unit means being effective to produce a received signal having multiple cycles therein corresponding to said received energy, receiving means coupled to said receiving search unit means, said last means being responsive to the timing of the individual cycles within said received signal and the transmission of said burst of ultrasonic energy, sampling means in said receiving means for sampling the received signal during an individual cycle at a predetermined sample time to produce an output signal, said output signal being a function of the individual cycles within the received signal during said predetermined sample time, and meAns coupled to said sampling means and responsive to the transmission of said burst of ultrasonic energy, said means being effective to actuate said sampling means at a predetermined time after the transmission of said burst whereby said output signal is a function of the received signal during said sample time.

Claim 30

A material tester for inspecting a workpiece, said material tester including transmitting search unit means for transmitting a multicycle burst of ultrasonic energy into the workpiece, receiving search unit means for receiving said energy from said workpiece, said receiving search unit means being effective to produce a received signal having multiple cycles therein corresponding to said received energy, receiving means coupled to said receiving search unit means, said last means being responsive to the timing of the individual cycles within said received signal and the transmission of said burst of ultrasonic energy, sampling means in said receiving means for sampling the received signal during an individual cycle at a predetermined sample time to produce an output signal, said output signal being a function of the individual cycles within the received signal during said predetermined sample time, and meAns coupled to said sampling means and responsive to the transmission of said burst of ultrasonic energy, said means being effective to actuate said sampling means at a predetermined time after the transmission of said burst whereby said output signal is a function of the received signal during said sample time.

Claim 31

A material tester for inspecting a workpiece, said material tester including a transmitter effective to produce a timing pulse, transmitting search unit means coupled to said transmitter for transmitting a multicycle burst of ultrasonic energy into the workpiece in response to said timing pulse, receiving search unit means for receiving said burst of energy from said workpiece whereby the individual cycles of said received energy have a time displacement which is a function of the characteristics of the workpiece, said receiving search unit means being effective to produce a received signal corresponding to said received energy, said received signal including a pulse having a multiple cycle therein wherein the individual cycles in said received signal have a time displacement from the individual cycles in the transmitted burst which is a function of said characteristics of the workpiece, means coupled to said transmitter and said receiving search unit means, said last means being responsive to the time displacement of a portion of the individual cycles in said received signal relative to said timing pulse to produce a second signal which is a function of the characteristics of the workpiece, sampling means in said last means for sampling the received signal, and time delay means coupled to said sampling means and responsive to a timing pulse to actuate the sampling means a predetermined time after the transmission of said burst of ultrasonic energy whereby the received signal is sampled during an individual cycle thereof to produce an output signal which is a function of the timing of the individual cycles within the received signal.

Claim 32

A material tester for inspecting a workpiece, said material tester including a transmitter effective to produce a timing pulse, transmitting search unit means coupled to said transmitter for transmitting a multicycle burst of ultrasonic energy into the workpiece in response to said timing pulse, receiving search unit means for receiving said burst of energy from said workpiece whereby the individual cycles of said received energy have a time displacement which is a function of the characteristics of the workpiece, said receiving search unit means being effective to produce a received signal corresponding to said received energy, said received signal including a pulse having a multiple cycle therein wherein the individual cycles in said received signal have a time displacement from the individual cycles in the transmitted burst which is a function of said characteristics of the workpiece, means coupled to said transmitter and said receiving search unit means, said last means being responsive to the time displacement of a portion of the individual cycles in said received signal relative to said timing pulse to produce a second signal which is a function of the characteristics of the workpiece, sampling means in said last means for sampling the received signal, and time delay means coupled to said sampling means and responsive to a timing pulse to actuate the sampling means a predetermined time after the transmission of said burst of ultrasonic energy whereby the received signal is sampled during an individual cycle thereof to produce an output signal which is a function of the timing of the individual cycles within the received signal.

Claim 33

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, transmitting search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of ultrasonic energy into the workpiece, receiving search unit means effective to receive said burst of energy from said workpiece, said receiving search unit means being effective to produce a multicycle signal corresponding to said burst and having a time duration corresponding to the duration of said burst, a receiver coupled to said receiving search unit means and responsive to the signal therefrom to produce a multicycle received signal, means in said receiver coupled to the transmitter, said last means being responsive to said received signal at a predetermined reference time after said driving signal for a predetermined sample time shorter than the duration of said burst and effective to produce an output signal which is a function of the variations in the instantaneous value of said received signal. said last means includes means for sampling said received signal at said predetermined reference time for said predetermined sample time and means for holding said sample whereby the output signal is a function of the value of the received signal during said sample time.

Claim 34

A material tester for inspecting a workpiece, said material tester including a transmitter for producing a driving signal, transmitting search unit means coupled to said transmitter and responsive to said driving signal for transmitting a multicycle burst of ultrasonic energy into the workpiece, receiving search unit means effective to receive said burst of energy from said workpiece, said receiving search unit means being effective to produce a multicycle signal corresponding to said burst and having a time duration corresponding to the duration of said burst, a receiver coupled to said receiving search unit means and responsive to the signal therefrom to produce a multicycle received signal, means in said receiver coupled to the transmitter, said last means being responsive to said received signal at a predetermined reference time after said driving signal for a predetermined sample time shorter than the duration of said burst and effective to produce an output signal which is a function of the variations in the instantaneous value of said received signal. said last means includes means for sampling said received signal at said predetermined reference time for said predetermined sample time and means for holding said sample whereby the output signal is a function of the value of the received signal during said sample time.

Claim 35

A material tester for inspecting a workpiece, said material tester including a transmitter effective to produce a timing pulse, transmitting search unit means coupled to said transmitter for transmitting a multicycle burst of ultrasonic energy into the workpiece in response to said timing pulse, receiving search unit means for receiving said burst of energy from said workpiece whereby the individual cycles of said received energy have a time displacement which is a function of the characteristics of the workpiece, said receiving search unit means being effective to produce a received signal cOrresponding to said received energy, said received signal including a pulse having multiple cycles therein wherein the individual cycles in said received signal have a time displacement from the individual cycles in the transmitted burst which is a function of said characteristics of the workpiece, means coupled to said transmitter and said receiving search unit means, said last means being responsive to the time displacement of a portion of the individual cycles in said received signal relative to said timing pulse to produce a second signal which is a function of the characteristics of the workpiece, said last means includes means responsive to the time the instantaneous value of the received signal equals a predetermined amount and means responsive to the time delay between the transmission of said burst of ultrasonic energy and the time the said instantaneous value occurs whereby said output signal is a function of the time the instantaneous value equals said predetermined amount.

Claim 36

A material tester for inspecting a workpiece, said material tester including a transmitter effective to produce a timing pulse, transmitting search unit means coupled to said transmitter for transmitting a multicycle burst of ultrasonic energy into the workpiece in response to said timing pulse, receiving search unit means for receiving said burst of energy from said workpiece whereby the individual cycles of said received energy have a time displacement which is a function of the characteristics of the workpiece, said receiving search unit means being effective to produce a received signal cOrresponding to said received energy, said received signal including a pulse having multiple cycles therein wherein the individual cycles in said received signal have a time displacement from the individual cycles in the transmitted burst which is a function of said characteristics of the workpiece, means coupled to said transmitter and said receiving search unit means, said last means being responsive to the time displacement of a portion of the individual cycles in said received signal relative to said timing pulse to produce a second signal which is a function of the characteristics of the workpiece, said last means includes means responsive to the time the instantaneous value of the received signal equals a predetermined amount and means responsive to the time delay between the transmission of said burst of ultrasonic energy and the time the said instantaneous value occurs whereby said output signal is a function of the time the instantaneous value equals said predetermined amount.

Claim 37

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle burst of energy into the workpiece and receiving said energy from said workpiece whereby the individual cycles of the received energy have a time displacement from the individual cycles of the transmitted burst which is a function of the characteristics of the workpiece, said search unit means being effective to produce a received signal corresponding to said received energy whereby the individual cycles in said received signal having a time displacement which is a function of said characteristics of the workpiece, means coupled to said search unit means and responsive to said time displacement of the individual cycles in said signal to produce a second signal which is a function of the characteristics of the workpiece, and sampling means in said last means responsive to the transmission of said burst of energy and effective to sample the received signal during a sample interval to produce an output signal, said sample interval occurring a predetermined time interval after the transmission of said burst and having a time duration which is shorter than the duration of said transmitted burst whereby the output signal is a function of the timing of the individual cycles within the received signal.

Claim 38

A material tester for inspecting a workpiece, said material tester including search unit means for transmitting a multicycle burst of energy into the workpiece and receiving said energy from said workpiece whereby the individual cycles of the received energy have a time displacement from the individual cycles of the transmitted burst which is a function of the characteristics of the workpiece, said search unit means being effective to produce a received signal corresponding to said received energy whereby the individual cycles in said received signal having a time displacement which is a function of said characteristics of the workpiece, means coupled to said search unit means and responsive to said time displacement of the individual cycles in said signal to produce a second signal which is a function of the characteristics of the workpiece, and sampling means in said last means responsive to the transmission of said burst of energy and effective to sample the received signal during a sample interval to produce an output signal, said sample interval occurring a predetermined time interval after the transmission of said burst and having a time duration which is shorter than the duration of said transmitted burst whereby the output signal is a function of the timing of the individual cycles within the received signal.