Ultrasonic inspection system with scanned multiple transducers

Claim 1

Ultrasonic inspection system for testing a test piece along incremental paths and capable of determining one or more types of physical properties of the testpiece along each incremental path, comprising: a. search unit means including a plurality of transducers each of which is acoustically coupled to the test piece at a different incremental path, b. a clock for producing a single source of sequential triggering pulses, c. a counter connected to the clock for producing a sequence of channel selecting signals at a plurality of outputs in response to only said triggering pulse, said selecting signals having correspondence with said incremental paths, d. a plurality of gated pulser/prereceiver combinations, each coupled to said counter and directly connected to a different trans-ducer for sequentially scanning selectively either adjacent or non-adjacent incremental paths of said testpiece, each said combination comprising: 1. a separate pulser for energizing each different transducer, 2. a separate prereceiver for preamplifying the electrical signals generated by said transducer and adapted to effectively isolate said transducer output from subsequent circuitry when deenergized, 3. a first control gate adapted to pass a distinctive channel selecting signal to activate both said pulser and prereceiver in addition to at least one other device by momentarily switching all said devices on from a normally off condition, e. a main receiver directly connected to each said prereceiver for receiving a sequence of said preamplified electrical signals therefrom and issuing amplified electrical signals including a defect pulse echo signal occurrable between front and rear surface pulse echo signals associated with each said incremental path, f. sampling gating means coupled to said receiver and said clock for producing at least one sequence of gated defect and rear surface pulse echo signals after said triggering pulse and during corresponding defect and rear surface gating intervals of sufficient duration to evaluate any one incremental path, said gating means also issuing said triggering pulse and a rear surface gating interval pulse, g. pulse echo signal amplitude discriminating means coupled to said sampling gating means for producing one or more echo initiated output signals synchronized with the rear surface gating interval pulse and terminated by said triggering pulse, said signal discriminating means including a detecting circuit for each said one or more discriminating means outputs for detecting signal amplitude changes such as amplitude transposition, amplitude transposition sequence, and amplitude ratio of each said defect pulse echo signal relative said rear surface pulse echo signal, said discriminating means output signals corresponding to one or more predetermined physical properties of said test piece, and h. means for utilizing one or more of the discriminating means output signals to determine one or more physical properties of said test piece, said means including a plurality of second control gates activated sequentially by said channel selecting signals to identify one or more types of physical properties with each incremental path of said test piece.