The present invention relates to a device that has the purpose of making accurate measurements on a distant object by means of the interference of a single coherent light beam focused and continuous on the object itself. Peculiarity of the invention consists in the auto-calibration procedure in the field. A further peculiarity of the invention consists in the ability to compensate for changes in the geometry of the system due to changes in internal and environmental temperature. The invention is also characterized by the possibility of being installed on a computerized device of the portable type (e.g. smartphones and tablets). The measuring system, in its preferred form of implementation, is constituted by a laser generator (1), an infrared temperature sensor (2), an electronic control card (5) fed by means of a group of batteries (3) interfaced to a smartphone (8) through communication channel integrated in the control electronics (5). For the shot of the object to be measured the camera (6) and possibly fl
