13-12-1938 дата публикации
Номер: GB497095A
Автор:
497,095. Magnetic tests. UNGER, F., and HILPERT, R. S. June 16, 1937, Nos. 16728 and 16729. Convention dates, June 17, 1936 and Jan. 15, 1937. [Class 37] Apparatus for indicating the disposition of a magnetic field, e.g. in magnetic tests, comprises a suspension of ferromagnetic particles in a fluid enclosed in a testing vessel made partly or wholly flexible, whereby the vessel may make better contact with articles to be tested for faults. The vessel may be made of thin metal, celluloid, artificial resin, artificial glass or of other synthetic substances, and of any convenient shape. Fig. 1 shows a shallow testing vessel g having an opaque bottom u and a transparent top o completely filled with, for example, ferromagnetic particles suspended in water, and provided with an expansion vessel A to avoid undue liquid pressures when the vessel is distorted. The bottom u may alternatively be transparent in which case a lightsensitive film may be disposed between the article under test and the bottom u, and illuminated through the vessel for photographing the field pictures, although with suitable suspensions the field pictures remain for some time and may be photographed after removal of the test vessel from the article under test. In testing a welded joint s, Fig. 2, between plates w, the vessel g is placed over the weld and the plates w magnetized by a permanent magnet m placed as shown or on the opposite side of the plates w. Welded angle joints, or an annular flange weld s<1>, Fig. 4, &c. are tested by a vessel g<2>, shaped to fit the angle, and an electromagnet e with pivotally adjustable polepieces p<1>, p<2> is used to magnetize the test piece. A shaft may be tested by applying a curved vessel to the periphery thereof and magnetizing the shaft by passing D.C. or A.C. therethrough. For testing grooved objects, the test vessel has a curved bottom f, Fig. 6 ; the suspension is located between the bottom f and an intermediate bottom z, and a ...
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