System for inspecting a welded seam with means for generating a signal which is a function of the welding temperature

Abstract

Abstract THE PRESENT INVENTION RELATES TO NONDESTRUCTIVE TESTING AND MORE PARTICULARLY TO MEANS FOR LOCATING DEFECTS IN A WORKPIECE, SUCH AS WELDED PIPE, DETERMINING WHETHER OR NOT THE DEFECT IS UNACCEPTABLE AND INDICATING THE CHARACTERISTICS AND LOCATION OF SUCH DEFECTS. A SEARCH UNIT HAVING A SPINNING DISC OR ROTOR IS DISPOSED ADJACENT THE WORKPIECE SO AS TO SCAN ALONG AN INSPECTION AREA ON THE WORKPIECE. A FIRST PICKUP PROBE ON THE ROTOR SENSES ANDY STRAY MAGNETIC FIELDS PRODUCED BY ANY INSIDE OR OUTSIDE DEFECTS, SUCH AS CRACKS, TOGETHER WITH MEANS TO INDICATES THE SIZE AND LOCATION OF THE DEFECT. A SECOND PICKUP PROBE ON THE ROTOR SCANS THE WORKPIECE AND SENSES THE MAGNETIC RERADIATED FROM THE EDDY CURRENTS INDUCED IN THE SURFACE OF THE WORKPIECE. MEANS ARE COUPLED TO THE TWO PROBES AND RESPONSIVE TO THE SIGNALS THEREFROM TO MAINTAIN THE SEARCH UNIT CORRECTLY CENTERED OVER THE INSPECTION AREA, TO DETERMINE VARIOUS CHARACTERISTICS OF THE WORKPIECE AND INDICATE WHEN UNACCEPTABLE DEFECTS ARE PRESENT.

Inventors

• 👤 Friedrich M O Forster

Bibliographic Details