Patent ID: 6840108

Claim:
A method for inspecting a package seal of a package using an airborne ultrasonic system including at least one airborne ultrasonic transmitting transducer and at least one airborne ultrasonic receiving transducer, the method including, in a gaseous environment, mounting the at least one airborne ultrasonic transmitting transducer on one side of the package seal and mounting the at least one airborne ultrasonic receiving transducer on an opposite side of the package seal, providing relative movement between a package and said at least one airborne ultrasonic transmitting transducer and said at least one airborne ultrasonic receiving transducer so that the package moves between the at least one airborne ultrasonic transmitting transducer and the at least one airborne ultrasonic receiving transducer, directing ultrasonic energy in a non-liquid environment toward the package seal from the at least one airborne ultrasonic transmitting transducer to the at least one airborne ultrasonic receiving transducer as there is relative movement therebetween while preventing ultrasonic energy from passing about an edge of the package adjacent the seal toward the at least one airborne ultrasonic receiving transducer, and using the energy received at the at least one airborne ultrasonic receiving transducer to provide a signal to a device to thereby obtain an indication of integrity of the seal.