A device for non-destructive testing of a component by analyzing radiation dissipation when the component is stressed by mechanical stresses. The device includes measuring means for determining a surface radiation field of the component. The measuring means are integrated in a flexible housing for covering a region of the surface of the component to be tested. The device enables an initial crack upon stress concentration on a surface of the component and the presence of a crack upon propagation of the crack to be detected. The disclosed embodiments are useful for non-destructive testing of aircraft components, but may be used in all industrial sectors where testing the integrity of components is important, such as the automotive, railway, marine and nuclear industries.