Inspection mode switching circuit

An eddy current probe testing apparatus for a nuclear reactor pressure vessel, said nuclear reactor pressure vessel being a body with a surface, said eddy current probe testing apparatus comprising:

• a robotic arm disposed within said nuclear reactor pressure vessel, said robotic arm having an end effector sled;
• said end effector sled having a body with a plurality of couplings;
• at least one eddy current, probe structured to operate in an first mode and a second mode to detect defects in a body having a surface, said eddy current probe having a first coil and a second coil, said first coil extending in a plane substantially perpendicular to a portion of said body surface, said second coil extending in a in a plane substantially perpendicular to said body surface and to said first coil;
• said first coil having a first terminal and a second terminal;
• said second coil having a first terminal and a second terminal;
• a signal producing device structured to produce at least one test signal for said at least one eddy current probe;
• an output device structured to convert at east one output sign from said at east one eddy current probe to a displayable format;
• a ground bus;
• and
• a switch assembly having a plurality of switches structured to provide electrical signals from said signal producing device to said first coil and said second coil, said plurality of switches structured to move rapidly between a first configuration, wherein said eddy current probe acts in a driver pick-up mode, and a second configuration, wherein said eddy current probe acts in an impedance mode, whereby said eddy current probe acts in both modes concurrently.

A method of performing an inspection of a nuclear reactor pressure vessel, said nuclear reactor pressure vessel being a body with a surface, said method comprising the steps of:

• providing a signal producing device;
• providing a probe with first and second coils of a conductive material;
• positioning an end effector inspection sled having at least one eddy current probe within said nuclear reactor pressure vessel with said at least one eddy current probe disposed adjacent said nuclear reactor pressure vessel body;
• performing an inspection of said nuclear reactor pressure vessel body using said at least one eddy current probe;
• wherein one eddy current probe acts concurrently in a driver pick-up mode, wherein said probe first coil is coupled to, and in electronic communication with, said signal producing device and the second coil is grounded, and an impedance mode, wherein both probe first and second coils are coupled to, and in electronic communication with, said signal producing device.

A method of performing an inspection of a nuclear reactor pressure vessel, said nuclear reactor pressure vessel being a body with a surface, said method comprising the steps of:

• providing an eddy current probe testing apparatus having a robotic arm, an eddy current probe, an end effector sled, a signal producing device, and a mode switching circuit, said sled coupled to said robotic arm, said eddy current probe disposed on said sled, said signal producing device coupled to, and in electronic communication with, said mode switching circuit, said mode switching circuit coupled to, and in electronic communication with, said eddy current probe, said mode switching circuit structured to be switched between a first configuration, wherein said eddy current probe acts in a driver pick-up mode, and a second configuration, wherein said eddy current probe acts in an impedance mode;
• positioning said end effector inspection sled having said eddy current probe within said nuclear reactor pressure vessel with said eddy current probe disposed adjacent said nuclear reactor pressure vessel body;
• performing an inspection of said nuclear reactor pressure vessel body using said eddy current probe;
• and
• during said inspection, said mode switching circuit alternating between said first and second configurations whereby said eddy current probe acts concurrently in a driver pick-up mode and an impedance mode.