Sampling system with a replaceable cassette assembly and methods of using the same
A sampling system can include a cassette assembly coupled to a station base that has a plurality of actuators. The cassette assembly can include a cassette base, a cassette top, and an elastomer membrane disposed between the cassette base and cassette top. The cassette base can include a sample inlet, a reservoir for receiving a sample from the sample inlet, a sample outlet, and a fluid flow path extending between the sample inlet, the reservoir, and the sample outlet.
1 . A sampling system for collecting a fluid sample from an enclosed container comprising: a station base having a pump member with a cassette-receiving surface and a plurality of actuators, the plurality of actuators including at least a first actuator, a second actuator, a third actuator, and a fourth actuator; wherein the plurality of actuators comprise pneumatic air cylinders or electric actuators, and a removable, unitary cassette assembly received on the cassette-receiving surface, the cassette assembly comprising:
a cassette top having an air inlet disposed over a location of a variable volume reservoir and in engagement with the pump member to vary a pressure at a pump membrane;
a cassette base comprising:
a sample inlet,
the variable volume reservoir, defined by a cavity within the cassette base and the cassette top, for receiving a sample from the sample inlet,
a sample outlet, and a downstream fluid flow path, for delivering a gas, a sanitizing agent, or a sample, that extends between the sample inlet, the reservoir, and the sample outlet, a sanitizing fluid inlet, and a gas inlet, the sanitizing fluid inlet and the gas inlet being upstream of the sample inlet;
the cassette top comprising a plurality of movable members that are in engagement with respective ones of the plurality of actuators, the plurality of movable members comprising: a first movable member that is in engagement with the first actuator, a second movable member that is in engagement with the second actuator, a third movable member that is in engagement with the third actuator, and a fourth movable member that is in engagement with the fourth actuator; and an elastomer membrane disposed between the cassette base and the cassette top; wherein the elastomer membrane extends over the reservoir and provides a pump membrane that is movable to vary a volume of the reservoir, wherein the first movable member is in contact with the elastomer membrane to provide a sample inlet valve that can be opened and closed by a movement of the first actuator, and the second movable member is in contact with the elastomer membrane to provide a sample outlet valve that can be opened and closed by a movement of the first actuator, and wherein the third movable member is in contact with the elastomer membrane to provide a sanitizing fluid inlet valve that can be opened and closed by a movement of the third actuator, and the fourth movable member is in contact with the elastomer membrane to provide a gas valve that can be opened and closed by a movement of the fourth actuator.
2 . The sampling system of claim 1 , wherein the station base further comprises one or more attachment members for securing the cassette assembly to the cassette-receiving surface.
3 . The sampling system of claim 2 , wherein the one or more attachment members comprise clamp members or other locking members that restrict movement of the cassette assembly when received on the station base.
4 . The sampling system of claim 1 , wherein wetting components of the sampling system are in the cassette assembly and, other than a sample line out, the station base does not come into direct contact with the sample during operation.
5 . The sampling system of claim 1 , wherein the plurality of moveable members are a rocker valve, the rocker valve comprising a rocker arm that is in engagement with a respective one of the plurality of actuators and a curved member that is in contact with the elastomer membrane.
6 . The sampling system of claim 5 ,
wherein each of the rocker arms is movable from a first position in which the respective valve is closed and a second position in which the respective valve is open, and
wherein each of the rocker arms has a first end in engagement with a respective one of the plurality of actuators and a second end that is in contact with a spring member, the spring member biasing the rocker arm to the first position.
7 . The sampling system of claim 5 ,
wherein each of the rocker arms is movable from a first position in which the respective valve is closed and a second position in which the respective valve is open, and
wherein each of the rocker arms has a first end in engagement with a respective one of the plurality of actuators and a second end that is in contact with a spring member, the spring member biasing the rocker arm to the second position.
8 . The sampling system of claim 1 , wherein the elastomer membrane comprises silicone, EPDM, Viton, or CFLEX.