Patent ID: 7591979

Claim:
A device for detecting toxic agents in a liquid medium comprising: a body comprising at least one portion that is submerged into a liquid medium, an inlet for introducing a sample of the liquid medium to an interior of the body, and an outlet for ejecting the sample of the liquid medium; a first reservoir within said body comprising a first opening in an upper surface of the first reservoir, a second opening present in a sidewall of the first reservoir, and a first reservoir drain present in a base surface of the first reservoir, wherein the inlet in the body is in fluid communication with the first opening of the first reservoir; a fluorometer for measuring photosynthetic activity of organisms in the sample of the liquid medium, the fluorometer comprising an inlet in fluid communication with the second opening of the first reservoir and a fluorometer drain; a pump in fluid communication with the fluorometer drain, the first reservoir drain, and the outlet of the body; a valve system configured to open and close the fluorometer drain and the first reservoir drain; and an electronics package in communication with the valve system, the pump and the fluorometer, wherein during a first time period the electronics package is configured to activate the pump, close the fluorometer and open the reservoir drain to draw the sample of liquid medium into the reservoir, and during a second time period the electronics package is configured to open the drain from the fluorometer and close the reservoir drain to draw the sample of the liquid medium into the fluorometer for the measuring of the photosynthetic activity of photosynthetic organisms in the sampe of the liquid medium, and during a third time period the electronics package is configured to close the drain from the fluorometer and open the drain from the sample reservoir to expel the sample of the liquid medium through the outlet of the body so that less than 10% of a subsequent sample is mixed with the sample of the liquid medium.