[en] The p-scan system (projection image scanning) is a step in the direction of achieving a more reliable ultrasonic inspection of weldings which is more independent of the operator and easier to be reproduced. The p-scan equipment is based on microcomputer-controlled ultrasonic equipment measuring, analyzing and recording all of the reflected signals of the welds inspected. All the echos of welding defects greater than a resolution of 1 dB are measured and recorded together with the associated positions. Defect positions are represented as projections of the defects in one or several projection charts. Mostly two charts are used: one parallel to the surface and one normal to the surface parallel to the weld. The defects thus can be seen in top view and in side view. The working principle is presented and examples for applications are shown. (orig.)