Fraunhofer Institute for Nondestructive Testing IZFP 
Computed tomography (CT) is a contact-free inspection method to provide three-dimensional volume images by means of X-rays. Due to the underlying physics, CT is particularly suited to precisely determine the position of small defects inside the object volume, achieving superior accuracy compared to ultrasonic or thermographical results. Depending on object size, material, and geometry, resolutions up to a few microns can be achieved. Typical applications concern the inspection of components to find defects such as pores, cracks or inclusions. Another field of application is the determination of an object‘s volume structure with subsequent analysis of the material composition and functionality.
The use of image processing software allows the automated detection and evaluation of pores inside the volume. Our CT scanners achieve a resolution of 3 μm in case of components up to 30 cm in diameter and up to 8 kg in weight. Big planar parts up to 150 cm diameter and up to 300 kg weight can be analysed computed laminography (CL) at a resolution up to 20 μm. Smaller objects of this type (up to 40 × 40 cm2) can be inspected with a resolution up to 1 μm and an inspection area of 2 × 2 mm2.
The maximum resolution mainly depends on the geometry and the material composition of the object to be inspected.
