Compressor impellers in turbines have to withstand a lot. They not only increase the pressure of vast amounts of gases and liquids, but are themselves subject to extreme centrifugal forces. If a compressor impeller fails due to material fatigue, it can destroy an entire turbine. Subsequently, the ability to calculate the load limits of components is of extreme importance to manufacturers. The results of these calculations, however, also need to be tested in the real world. Physicists at the TU Muenchen’s FRM II neutron source have now developed an appropriate test procedure that does just this. The STRESS-SPEC instrument at FRM II enables scientists to detect stresses hidden deep within large components.