Apparatus and method for electromagnetically distinguishing between outside and inside flaws in magnetizable members utilizing a leakage field detector

Claim 1

AN APPARATUS FOR TESTING A MAGNETIZABLE MEMBER FOR BOTH INSIDE AND OUTSIDE DEFECTS AND PROVIDING A READOUT FOR SUCH DEFECTS, COMPRISING A MAGNETIZING MEANS FOR PRODUCING A UNIDIRECTIONAL MAGNETIC FIELD IN THE WALL OF SAID MEMBER, MAGNETIC RESPONSIVE MEANS POSITONED AJDACENT THE OUTSIDE SURFACE OF SAID WALL FOR PRODUCING ELECTRICAL DEFECT SIGNALS IN RESPONSE TO VARIATINS IN FLUX LEAKAGE FROM SAID WALL, MEANS FOR PROGRESSIVELY AND RELATIVELY MOVING SAID MAGNETIC RESPONSIVE MEANS ADJACENT TO SAID WALL DURING TESTING, AND A LOGIC CIRCUIT FOR INDICATING THE RELATIVE SIZE AND LOCATION OF DEFECTS IN SAID WALL COMPRISING ELECTRICAL MEANS CONNECTED TO SAID MAGNTIC RESPONSIVE MEANS FOR PRODUCING FIRST ELECTRICAL IMPULSES WHEN SAID DEFECT SIGNALS ARE ABOVE A PRESELECTED LEVEL AND FOR PRODUCING SECOND ELECTRICAL IMPULSES WHEN THE HIGH FREQUENCY COMPONENTS OF SAID DEFECT SIGNALS ARE ABOVE ANOTHER PRESELECTED LEVEL, SAID ELECTRICAL MEANS INCLUDING MEANS FOR INVERTING ONE OF SAID FIRST AND SECOND ELECTRICAL IMPULSES TO PRODUCE THIRD ELECTRICAL IMPULSES, FIRST AND SECOND ELECTRICAL INDICATOR DEVICES CONNECTED TO RECEIVE SAID FIRST, SECOND AND THIRD ELECTRICAL IMPULSES SUCH THAT SAID FIRST DEVICE INDICATES OUTSIDES SURFACE DEFECTS AND SAID SECOND DEVICE INDICATES INSIDE SURFACE DEFECTS.

Claim 2

AN APPARATUS FOR TESTING A MAGNETIZABLE MEMBER FOR BOTH INSIDE AND OUTSIDE DEFECTS AND PROVIDING A READOUT FOR SUCH DEFECTS, COMPRISING A MAGNETIZING MEANS FOR PRODUCING A UNIDIRECTIONAL MAGNETIC FIELD IN THE WALL OF SAID MEMBER, MAGNETIC RESPONSIVE MEANS POSITONED AJDACENT THE OUTSIDE SURFACE OF SAID WALL FOR PRODUCING ELECTRICAL DEFECT SIGNALS IN RESPONSE TO VARIATINS IN FLUX LEAKAGE FROM SAID WALL, MEANS FOR PROGRESSIVELY AND RELATIVELY MOVING SAID MAGNETIC RESPONSIVE MEANS ADJACENT TO SAID WALL DURING TESTING, AND A LOGIC CIRCUIT FOR INDICATING THE RELATIVE SIZE AND LOCATION OF DEFECTS IN SAID WALL COMPRISING ELECTRICAL MEANS CONNECTED TO SAID MAGNTIC RESPONSIVE MEANS FOR PRODUCING FIRST ELECTRICAL IMPULSES WHEN SAID DEFECT SIGNALS ARE ABOVE A PRESELECTED LEVEL AND FOR PRODUCING SECOND ELECTRICAL IMPULSES WHEN THE HIGH FREQUENCY COMPONENTS OF SAID DEFECT SIGNALS ARE ABOVE ANOTHER PRESELECTED LEVEL, SAID ELECTRICAL MEANS INCLUDING MEANS FOR INVERTING ONE OF SAID FIRST AND SECOND ELECTRICAL IMPULSES TO PRODUCE THIRD ELECTRICAL IMPULSES, FIRST AND SECOND ELECTRICAL INDICATOR DEVICES CONNECTED TO RECEIVE SAID FIRST, SECOND AND THIRD ELECTRICAL IMPULSES SUCH THAT SAID FIRST DEVICE INDICATES OUTSIDES SURFACE DEFECTS AND SAID SECOND DEVICE INDICATES INSIDE SURFACE DEFECTS.