Holographic attachement for a machine for determing the field of displacements

The application of holographic methods to mechanical testing on a broad scale is hampered by the necessity of placing the loading device on the plate of the holographic unit. The loading device here must be specially designed. Since the device's stand is in most cases insufficiently rigid, pictures of interference bands are obtained which include information not only on the displacement of the points of the sample's surface during its deformation but also on the rotations and displacements of the sample in the clamps. A holographic attachment developed for a certain test machine to cope with this problem is described.