Magnetic particle testing - Practical aspects

Introduced in 1922, magnetic particle testing is constantly being developed to increase the probability of detecting discontinuities, and to improve health, safety and environmental protection conditions. Magnetic testing products, accessories and equipment are constantly being perfected to achieve the highest levels of performance, while taking into account operators' concerns in terms of ergonomics.

Magnetic particle inspection (MPI) is the non-destructive testing (NDT) method par excellence, used to detect and locate surface and underlying (near-surface) discontinuities on ferromagnetic alloys.

It is used in all industrial sectors, virtually anywhere, including underwater, on site or in the workshop, in manufacturing or maintenance. Like all NDT methods, MT has its own limitations.

Despite its undeniable advantages, MT does not always enjoy a very good image. It suffers in comparison with other, more recent NDT methods, such as ultrasonic and eddy current testing, which are often complementary to it, but give a more noble image and are less painful for operators. Two of the criticisms often levelled at MT are the use of chemicals and the exposure of operators to ultraviolet radiation (or actinic blue light) and magnetic fields. However, if regulations on conditions of use and effluent treatment are followed, operators' health and the environment are protected, and MT remains a reliable, fast and cost-effective NDT method for inspecting parts and structures for safety.

This article deals with the practical aspects of magnetic particle testing. It is aimed at all users and anyone wishing to discover or learn more about this proven NDT method.