| 摘要 |
The present invention concerns a group (10) and method for measuring the pressure in closed containers (30) made from optically transparent material at least at a portion of a top space (31) thereof, and a filling and/or packaging plant (100) using the measuring group. In particular the present invention concerns a group and a method for contactlessly measuring the pressure in closed containers, able to be used directly in automatic filling and/or packaging plants operating at high speed, without the need to stop or slow down such plants or in any case to pick up the containers from the same. The measuring group for measuring the pressure in closed containers (30) made from optically transparent material at least at a portion of a top space (31) thereof, comprises at least one inspection area (20) adapted for the passage of at least one portion of a top space (31) of a closed container (30) of said closed containers; at least one laser source (11) with optical axis (A) for the emission of a laser beam at a wavelength tunable with an absorption wavelength of a gas contained in the top space (31) of the closed container (30), the at least one laser source (11) being positioned so as to direct the laser beam towards the at least one inspection area (20); at least one detector (12) positioned so as to detect at least one portion of the laser beam emitted by the laser source (11) once it has travelled through the inspection area (20) and to provide in output data representative of an absorption spectrum of said gas as a consequence of the passage of the laser beam through the inspection area (20); at least one device (14,14') for detecting the signal acquisition time period corresponding to the passage of said at least one portion of a top space (31) of a closed container (30) through the inspection area; and is characterised in that it comprises means (41) for identifying signal contributions useful for the pressure measurement amongst the data representative of an absorption spectrum acquired during the signal acquisition time period. |
