von Karman Institute for Fluid Dynamics 1 article published in JoVE Engineering Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron Bernd Helber1,2, Olivier Chazot1, Annick Hubin2, Thierry E. Magin1 1Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, 2Research Group Electrochemical and Surface Engineering, Vrije Universiteit Brussel Development of new ablative materials and their numerical modeling requires extensive experimental investigation. This protocol describes procedures for material response characterization in plasma flows with the core techniques being non-intrusive methods to track the material recession along with the chemistry in the reactive boundary layer by emission spectroscopy.