Abstract: Extraction device designed to extract a short-circuiting wedge inserted between two conductors to take an electrolysis cell offline. The extraction device includes a means of gripping said wedge and, in conjunction with the upper horizontal face of each conductor, at least one jack directed vertically and including a body and a stem, a) stem (or said body) being interdependent with at least one horizontal support face directed downwards and laid out so that, when said extraction device is placed above said wedge to extract it, the upper horizontal face of each conductor is in line with one horizontal support face, b) said body (or said stem) being connected to said means of gripping said wedge, so that, when said jack is actuated to extract the wedge, said jack exerts opposing forces on said conductors and said wedge, tending to separate them.

Abstract: Extraction device designed to extract a short-circuiting wedge inserted between two conductors to take an electrolysis cell offline. The extraction device includes a means of gripping said wedge and, in conjunction with the upper horizontal face of each conductor, at least one jack directed vertically and including a body and a stem, stem (or said body) being interdependent with at least one horizontal support face directed downwards and laid out so that, when said extraction device is placed above said wedge to extract it, the upper horizontal face of each conductor is in line with one horizontal support face, b) said body (or said stem) being connected to said means of gripping said wedge, so that, when said jack is actuated to extract the wedge, said jack exerts opposing forces on said conductors and said wedge, tending to separate them.

Abstract: An on-the-fly method for measuring the length, along an axis (z?z) of an anode (20) used in the production of aluminium by molten salt electrolysis in which: i) said anode is suspended from a gripping member (13a) which is fitted with a displacement sensor measuring the vertical position of the point of attachment (O); ii) said gripping member is moved vertically so that the lower surface (21a) of the anode passes through a plane (P) formed by n beams (f1, . . . , fi, . . . , fn) and, each time one of said beams i (i=1 to n) is disturbed by the lower surface of the anode passing through it, the vertical position hi of said point of attachment (O) is measured; iii) the angle of inclination zz? of the anode stem is measured and the distance between the point of attachment and the lower surface (21a) of the anode block (21) is deduced based on values measured hi (i=1 to n), and the inclination value of the anode stem.