Method and apparatus of measuring residual stress in metals and the amount of a known constituent

Claim 1

X-RAY DIFFRACTION APPARATUS FOR DETERMINING PERCENT RETAINED AUSTENITE IN A SPECIMENT CONTAINING MARTENSITE AND AUSTENITE CRYSTALLINE STRUCTURE COMPRISING X-RAY RADIATING MEANS, MEANS SUPPORTING SAID SPECIMEN AND SAID X-RAY RADIATING MEANS, FIRST, SECOND AND THIRD GONIOMETERS ROTATABLY MOUNTED ABOUT A COMMON AXIS, FIRST, SECOND AND THIRD DETECTOR MEANS MOUNTED ON SAID FIRST, SECOND AND THIRD GONIOMETERS RESPECTIVELY AT PREDETERMINED ANGULAR ORIENTATIONS RELATIVE TO THE SURFACE OF SAID SPECIMEN, SAID FIRST AND THIRD DETECTOR MEANS INCLUDING FIRST, SECOND AND THIRD DETECTOR TUBES, SAID FIRST AND SECOND DETECTOR TUBES RESPONSIVE TO X-RAY INTENSITY AT SEPARATE DIFFRACTION ANGLES, SAID SECOND DETECTOR MEANS INCLUDING A SINGLE DETECTOR TUBE, SAID THIRD DETECTOR TUBES BEING RESPONSIVE TO X-RAY INTENSITY AT A DIFFRACTION ANGLE MIDWAY BETWEEN SAID SEPARATE DIFFRACTION ANGLES, FIRST AND SECOND CONTROL TUBES OF SAID FIRST AND THIRD OF SAID FIRST AND SECOND TUBES OF SAID FIRST AND THIRD DETECTOR MEANS RESPECTIVELY, SAID CONTROL MEANS INCLUDING MOTOR MEANS FOR DRIVING SAID FIRST AND THIRD GONIOMETER TO POSITIONS WHERE EQUAL CORRECTED INTENSITES ARE DETECTED BY SAID FIRST AND SECOND TUBES RESPECTIVELY, AND MEANS RESPONSIVE TO THE INTENSITIES DETECTED BY SAID THIRD TUBES AND SAID SINGLE FOR INDICATING PERCENT RETAINED AUSTENITE.