Patent ID: 8873068

Claim:
A portable industrial instrument for performing, in an integrated and two-way manner, interferometric fringe projection and shearography, on an object to be tested, comprising: a two-way interferometer ( 1 ) including means to generate a bidirectional circularly polarized light beam; a coherent or quasi-coherent light projection device ( 2 ); a recording or imaging device ( 4 ); a first location ( 24 ) where said two-way interferometer ( 1 ) is positioned to be functionally associated with the coherent or quasi-coherent light projection device ( 2 ) and a second location ( 44 ) where said two-way interferometer ( 1 ) is positioned to be functionally associated with the recording or imaging device ( 4 ); a computational device ( 6 ), including a video and analysis display; an excitation device ( 5 ) dedicated to the shearographic or fringe projection measurements; so that, when the two-way interferometer ( 1 ) is associated with the coherent or quasi-coherent projection device ( 2 ) at the first location ( 24 ), the instrument is able to measure the 3D shape of the object by interferometric fringe projection, and, when the two-way interferometer ( 1 ) is associated with the recording or imaging device ( 4 ) at the second location ( 44 ), the instrument is able to perform shearographic measurements on the object, the direction of the traversing light beam in the interferometer ( 1 ) being reversed when shifting from one measurement configuration to the other one, the direction of the coherent or quasi-coherent light being reversed in the two operation modes, said instrument being characterised in that: the two-way interferometer ( 1 ) is reversible and symmetric about a Savart plate, which is central and a translation device ( 3 ) for precisely displacing said two-way interferometer ( 1 ) from said first location ( 24 ) to said second location ( 44 ) and from said second location ( 44 ) to said first location ( 24 ), comprising a rail that is curved on one of its ends, the curved end having an arc subtending a maximum angle of 90°, so that the precision displacement of the interferometer corresponds to a combination of a strict geometric translation with a rotation angle which does not exceed 45° so as to create a crossing between respective directions of an incident light beam and a reflected light beam, according to the same angle.