System and technique for detecting the presence of foreign material

A system, comprising:

• a conveyor operable to provide a process stream;
• one or more inspection devices operable to transmit pulses of focused ultrasound to interrogate the process stream and receive an off-angle ultrasound scattering response to interrogation with the ultrasound;
• and
• a processing device operable to determine presence of a foreign material in the process stream based on a comparison of the off-angle ultrasound scattering response to a predetermined threshold;
• wherein the inspection devices include a plurality of spaced receivers each operable to receive an off-angle ultrasound scattering response to interrogation with ultrasound from a common transmitter.

A method, comprising:

• interrogating a stream of foodstuff with ultrasound;
• detecting an off-angle ultrasound scattering response to said interrogating with a plurality of spaced ultrasound receivers;
• and
• determining if foreign material is present in the foodstuff based on the off-angle ultrasound scattering response.

A system comprising:

• a conduit having at least one flat wall operable to receive a process stream,
• one or more inspection devices operable to transmit ultrasound through the flat wall to interrogate the process stream,
• a plurality of spaced receivers each operable to receive an off-angle ultrasound scattering response to interrogation with the ultrasound;
• and
• a processing device operable to determine presence of a foreign material in the process stream based on a comparison of the off-angle ultrasound scattering response to a predetermined threshold.

A system comprising:

• a conduit defining a flow path having a portion with a generally rectangular cross section,
• one or more inspection devices operable to transmit ultrasound to interrogate a process stream in the generally rectangular portion of the flow path,
• a plurality of spaced receivers each operable to receive an off-angle ultrasound scattering response to interrogation with the ultrasound;
• and
• a processing device operable to determine presence of a foreign material in the process stream based on a comparison of the off-angle ultrasound scattering response to a predetermined threshold.

A system comprising:

• a conduit operable to receive a process stream,
• one or more inspection devices operable to interrogate a volume of material in the process stream with ultrasound,
• at least two receivers focused on substantially non-overlapping interrogated volumes of material each operable to receive an off-angle ultrasound scattering response to the interrogation;
• and
• a processing device operable to determine presence of a foreign material in the process stream and to provide an indication of the spatial location of the foreign material in the process stream based on a comparison of the off-angle ultrasound scattering response of each receiver to a predetermined threshold.