Magnetic powder inspection with UV light
The magnetic powder inspection is a common alternative of the penetration test. However, the magnetic particles inspection (crack detection) can only be performed on magnetizable materials, e.g. iron base material. The method uses the change in the artificially created magnetic field to detect cracks. In practice, a magnetic field is created with a yoke magnet, a permanent magnet or a magnet bench. In the magnetic field formed, the magnetic conductivity of the material changes in the vicinity of the crack. This change can be visualized using fluorescent magnetic particles. The magnetic particles must be applied to the surface in the form of a powder or liquid during magnetization. Various UV LED lamps can be used to detect defects caused by fluorescent magnetic particles. UV lamps with a low heat emission and a good thermal conductivity cover are ideal for magnetic bench testing while providing the necessary UV light intensity.
UV headlamps are popular tools for fluorescent magnetic powder inspection with yoke magnets. Using the UV headlamp the hands of the examiner are free so they can hold the aerosol bottle in one hand and the yokemagnet in the other.