Patent ID: 7435339

Claim:
A drainage device for a filter unit for microbiological testing of liquids, wherein said drainage device comprises: (a) a mechanical support comprising a reception head for receiving a filter unit including a membrane; (b) a suction pump connected to said mechanical support to aspirate a liquid substance contained in said filter unit; (c) a weight sensor on which said mechanical support is mounted and which is adapted to deliver a signal representative of the weight exerted by said mechanical support on said weight sensor; (d) a user interface for entering data relating to the drainage of said filter unit and/or to said liquid substance; and (e) a control unit connected to said suction pump, the weight sensor and said user interface, said control unit being adapted to determine, from said data, at least a first weight corresponding to a first representative signal; and in that, when said weight sensor supplies a signal corresponding to said first signal, said control unit starts operation of said suction pump so as to aspirate said liquid substance contained in said filter unit.