A method was developed for effective, efficient, non-destructive, in-situ sample processing. Pressure vessels are used for sample delivery and collection, a shaker is used to keep the particles suspended, a back pressure of argon gas is used to keep the system under pressure to regulate the flow, and flow restrictors and frits are used that never come into contact with the sample slurry to avoid clogs.
Two pressure vessels are connected by a piece of tubing with the sample delivery vessel fitted such that the tubing reaches close to the bottom of the vessel. The sample delivery vessel is also attached to a water pump via a valve. The collection vessel is connected to a T-junction, with the two remaining sides connected to an argon tank and a flow restrictor, each with its own valve.
After the soil sample is loaded in the sample delivery vessel and the system is closed, the entire system is pressurized with argon up to the water pump valve. The water pump is set to just above the gas pressure, and this valve and the flow restrictor valve are opened. This induces a flow of water into the sample delivery vessel at a rate determined by the differences in applied head pressures. The flow restrictor faces no risk of clogging because only gas flows through it. The sample delivery vessel is attached to a shaker to keep the slurry suspended for the length of the experiment.
This instrument addresses several difficulties in dealing with slurries and small volumes by eliminating any frits or flow restrictors, and shaking to keep the slurry suspended. It also adds the capability to pressurize the system. Each part of the instrument design can be miniaturized further from the prototype to make it flight compatible.