This paper outlines a completely new technique which could provide the basis of an instrument for the non‐contacting and non‐destructive determination of static and residual stresses in engineering components, assemblies and structures. The method has been given the acronym of TERSA, standing for Thermal Evaluation for Residual Stress Analysis and would be applicable to a range of metals, both ferrous and non‐ferrous and also to plastics. Some experimental work is described and results are presented which confirm the principle of the pro