Abstract: The device is characterized in that it comprises: one ring-shaped sensor (1) body comprising a main part (3) delimiting a sensor chamber (5) extended by a threaded part (6) as well as a skirt (4) around the sensing chamber (5) and defining a support surface (8) to be fixed on the wall (10) of the can or bag to be checked, a tubular connecting screw (2) coupled with continuous analyzing means and designed to cooperate with the sensor (1) body, and sensing means capable of cutting or perforating the wall (10) of the can or bag to be checked so as to allow the gases, if any emitted in this can or bag, to enter the internal conduit (11) of the connecting screw (2) to be sensed by the continuous analyzing means.

Abstract: The device is characterised in that the obturating means are constituted by an obturating screw (24) capable of co-operating with the whole set of mounting pieces (3) and, if required, with a ring-shaped obturating joint (25) and in that the capturing means are constituted by a threaded joining piece (25) to co-operate with the whole set of mounting pieces (3) by replacing the obturating screw (24) and, if required, the ring-shaped obturating joint (25) during the control, so as to break the imperviousness of the receiving cell (6) with respect to the container or box and comprising a perforation (34) linked to continuous analysing means so as to enable capture of the gas that has entered the receiving cell (6).