Abstract: A system for carrying out holographic interferometry utilizes the same pulsed laser both for the exposure of holograms and for the reconstruction of combined wavefronts resulting from the exposure of a test object to two time spaced laser pulses. This enables the real-time observation of fringes due to interference due to deformation of a test object between timed spaced laser pulses. Pulses used to reconstruct the combined wavefronts are synchronized to the field interval of a video camera associated with a frame grabber so that the combined image may be presented on a video monitor as a continuous flicker-free image. The combined wavefronts may be obtained from separately exposed holograms, from a hologram together with a direct image of an object produced by the same pulse used to reconstruct the hologram, or from a single hologram double exposed by two laser pulses.

Abstract: A method and device for indicating the swelling of a casing or the like having a wall with at least one generally planar portion prone to deformation by pressure buildup within the casing. The device comprises an elongate strip of visible frangible material adapted for spanning superposition with the planar portion of the wall and means for securing opposing ends of the frangible strip to the casing to restrict movement of the ends perpendicular to the planar portion of the wall. Increasing bulging of the wall deflects the frangible strip to the point of fracture thereof. In another embodiment, gaskets may be interposed between the ends of the frangible strip and the wall of the casing to provide a clearance therebetween, thus increasing the permissible degree of bulging of the wall which may occur before deflection of the frangible strip.

Abstract: A method is described and claimed for the replenishment of deuterium or tritium concentration in a laser isotope separation process for the production of D.sub.2 O, or for the recovery of tritium from contaminated D.sub.2 O or H.sub.2 O. A working compound is selectively photodissociated by a laser beam and is replenished by contacting an exchange liquid in a countercurrent fashion in a first contacting column. The exchange liquid is replenished with isotope by in turn being contacted with a feed stream in a second contacting apparatus. This second contacting apparatus may be a gas/liquid or liquid/liquid contacting apparatus and the countercurrent flows therein may be about equal or unequal.