Patent ID: 7794660

Claim:
A fluid content monitor comprising: a light transparent cuvette adapted to receive a fluid sample; a colorimeter adapted to direct light through the cuvette, receive the light passing through the cuvette, and generate a signal indicative of contents of the fluid sample based upon the received light; a container for holding a reagent; and a pump assembly including: a body having a side wall extending from an end wall to define a chamber, and openings in the side wall adjacent the end wall, a hammer mounted within the chamber of the body for reciprocating linear movement between a retracted position moved away from the end wall and an extended position moved against the end wall, an actuator operatively connected to the hammer, a reagent tube extending from the container to the cuvette for delivering reagent to the cuvette, wherein a resiliently flexible section of the reagent tube passes through the openings in the side wall of the pump body and extends through the chamber between the hammer and the end wall such that the resiliently flexible section is open when the hammer is in the retracted position and substantially closed when the hammer is in the extended position, an inlet check valve carried by the reagent tube between the reagent container and the pump to prevent reverse flow to the reagent container, and an outlet check valve carried by the reagent tube between the pump and the cuvette to prevent reverse flow to the pump.