A stereoscopic PIV system was build to study laminar turbulent transition in pipe flow. The PIV system is based on an angular displacement of the two cameras and a 3D calibration based reconstruction method. In order to measure the cross flow over the entire cross section of the pipe, the light sheet is perpendicular to the main flow direction. Measurements have shown that the PIV system is capable of detecting the laminar and turbulent flow fields over a large portion of the pipe cross section (fig.1), with increasing errors in the near wall region. In the error analysis, estimations and measurements of the registration error are shown (fig.2). The registration error is due to a small misalignment of the light sheet and the calibration plane. It is shown to make an important contribution to the total error. The transition measurements presented at the end of the paper are the result of brief test runs and are a good example of the kind of experiments planed for the near future. 三維立體PIV Imager pro X PIV相機 用于粒子成像測速(PIV)的熒光示蹤粒子