Combined optical system for dimensional and thermal measurements and operating method thereof

A combined optical system is described for determining the temperature of the surface of an object or material and its distance with respect to a predetermined reference point associated with the system, which comprises an optical radiation source adapted to emit at least one optical probe radiation at a predetermined wavelength or in a predetermined wavelength range, a source control unit arranged to alternately control the switching of the source from an operative condition, in which it emits an optical probe radiation, to an inoperative condition, in which it does not emit the optical probe radiation, optical detectors adapted to acquire at least one scattered optical radiation and one thermally emitted optical radiation from the surface of the object or material, and a processing unit synchronized with the control unit and arranged to determine the distance of the surface of the object or of the material on the basis of the optical probe radiation scattered from the surface of the object or material and received by the detectors when the source is operative and to determine the local temperature of the surface of the object or material on the basis of the optical radiation thermally emitted from the surface of the object or material received by the detectors when the source is inoperative.