An overview of diagnostic tools e test limiters and collector probes e used over the years for material migration studies in the TEXTOR tokamak is presented. Probe transfer systems are shown and their technical capabilities are described. this is accompanied by a brief presentation of selected results and conclusions from the research on material erosion e deposition processes including tests of candidate materials (e.g. W, Mo, carbon-based composites) for plasma-facing components in controlled fusion devices. the use of tracer techniques and methods for analysis of materials retrieved from the tokamak are summarized. the impact of research on the reactor wall technology is addressed.