Abstract: An optical assembly comprising a microscope (1) including a binocular (3) with a pair of oculars (4, 5), an optical body (8) and an objective lens (9) and an optical path; and an endoscope (2) provided with an extension (10), an outlet ocular (16) and an optical path. A commutating modulus (12, 13, 14; 18, 19, 14) is disposed between the binocular (3) and the optical body (8) of the microscope, and the outlet ocular (16) of the endoscope (2) as to enable an observer whose eyes are located at each ocular (4, 5) of the microscope (1) to observe selectively either: (a) the optical path of the microscope (1), or (b) the optical (or electronic) path of the endoscope (2), or (c) both optical paths simultaneously to scan an object to be investigated.

Abstract: As known the product to be heated (7) is made to scroll longitudinally in the flow of an inductor (IC) with a dual frequency along a longitudinal pitch and along a transverse pitch. According to the invention this produce is made to scroll in the flow of two successive inductors with a common transverse pitch (PT) which is adjustable (31a) practically between the two longitudinal pitches of these two inductors, this transverse pitch is set to make the width of this product coincide with an integer number of transverse pitches thus obtaining the same heating on the two edge areas (7a, 7b) of this product as on the intermediate areas, and firstly the ratio of the currents supplying these two conductors is set to homogenize the heating in each transverse pitch, and secondly the total power adjusted to reach the temperature required. The invention applies to metallurgy.