Magnetic Testing Essentials Quiz

Magnetic Testing Training Material Summary

• Black lights with a wavelength of 3.6x10-4 mm and intensity not less than 800 µW/cm2 are recommended for magnetic testing.
• Techniques for magnetic testing include selection of current type, particles, method of application, sequence, direction of field, sensitivity level, and equipment.
• Direct current is preferred for deeper penetration, while alternating current is more sensitive to surface defects.
• Dry particles are more sensitive to subsurface defects, while wet particles are more sensitive to very fine surface defects.
• Residual method and continuous method are two sequences for applying magnetic particles during testing.
• The direction of the magnetic field is decided based on the shape and orientation of the defect in relation to the part's principal axes.
• Sensitivity in magnetic testing depends on factors such as particle type, magnetizing current, and sequence.
• The equipment used for magnetic testing depends on the size, shape, and number of parts to be tested.
• Test surface preparation involves removing dirt, rust, loose scale, and oil or grease from the test area.
• The magnetic field should be verified before testing by using production or fabricated test parts with discontinuities or magnetic field indicators.
• Magnetic field indicators, like the "pie gage," are used to indicate field strength and direction at the surface in the area of the part under test.
• The effective area of coverage, overlap of effective areas, yoke placement for weld examination, and application of magnetic particles are crucial steps in magnetic testing.