(under subclass 214) Subject matter wherein the paramagnetic particles are used to test an object made of magnetic material and which includes means to magnetize the object to be tested to cause the parmagnetic particles, when upon the magnetized object, to become magnetized and adhere to the magnetized object or at a location where a discontinuity occurs when present in the object, the adhering magnetized particles arranging themselves in the pattern of the flux exiting from the object or in the pattern of a discontinuity when present in the object.
(1) Note. The magnetization may be caused by direct electrical current, by alternating current, by alternating and direct current, or by a permanent magnet.
(2) Note. A discontinuity is a flaw which includes a crack, fault, or other defect that is present in a tested object that is capable of changing the magnetization pattern known to be formed from a perfect object.
SEE OR SEARCH THIS CLASS, SUBCLASS:
213, for the detection of flaws by magnetizing a material with a magnetic recording medium thereon to record the field of the magnetized material.
215, for particles with additives to enhance the viewing of magnetized particles.
217+, for flaw detection of railroad rails.
452+, for the use of particles to test flaws by electrostatic forces. SEE OR SEARCH CLASS
73, Measuring and Testing,
632+, for flaw detection by means of compressional waves.
250, Radiant Energy,
358.1, for pipe inspection by invisible radiant energy, and for tire inspection by invisible radiation, subclasses 559.45+ for the photoelectric sensing of web, strand, or sheet material for defects by visible light.
356, Optics: Measuring and Testing, particularly
430+, for flaw detection in webs; and subclasses 237.1+ for flaw testing generally.
374, Thermal Measuring and Testing,
4+, for flaw detection by a thermal determination.
