Patent ID: 7399447

Claim:
An active sampler for liquids, comprising: an inlet; an outlet; a sampling unit positioned between said inlet and outlet, said sampling unit comprising a plurality of sampling chambers which are substantially fluidly sealed relative to one another, one of the chambers being positioned in a flow path that extends from the inlet, through the sampling unit, to the outlet, the flow path including a first flow path section and a second flow path section, the first flow path section extending between the inlet and one end of the sampling chamber, the second flow path section extending between the outlet and another end of the sampling chamber, the sampling chamber interfacing with the first and second flow path sections via resilient sealing members so as to substantially seal the sampling chamber in the flow path from the other sampling chambers; a pump configured to pump liquid selectively through said sampling chamber; and an actuator which rotates said sampling unit such that said one sampling chamber is positioned out of said flow path while another of the chambers is positioned in the flow path, wherein the sampling chambers contain a sampling media and liquid flows along the flow path, each of the first and second sections of the flow path being configured to have minimal flow restrictions such that the pump can produce a flow rate of at least about 10 ml/min through the sampling chamber while drawing generally on the order of about 250 mW of power, thereby permitting the sampling unit to operate over a longer period of time for a given battery charge.