Device for generating a magnetic field associable with a movable rod of a pneumatic actuator and method for making the device

A method for making a magnetic field generating device (1) associable with a movable rod (3) of a pneumatic actuator (2), the method comprising the operating steps of:

• taking a containment element (4) comprising an elongate portion (5) and a flange (6) positioned at a base (7) of the elongate portion (5), a housing (8) inside the elongate portion (5) and a mouth (9) of the housing (8), the flange (6) comprising an annular surface (11) extending mainly flat with an inner edge (12) surrounding the mouth (9) of the housing (8);
• inserting a magnet (10) in the housing (8) through the mouth (9) until the magnet (10) is completely inserted in the housing (8);
• inserting in the housing (8) through the mouth (9) a polymeric material in liquid or gel form until part of the polymeric material comes out of the mouth (9) of the housing (8) and extends beyond a main plane of extension of the annular surface (11);
• making the polymeric material solidify or leaving the polymeric material to solidify, creating an elastically deformable closing element (13) which is fixed to the containment element (4).