DEVICE FOR ANALYZING A FLUID MEDIUM

PCT No. PCT/DK94/00169 Sec. 371 Date Oct. 30, 1995 Sec. 102(e) Date Oct. 30, 1995 PCT Filed Apr. 28, 1994 PCT Pub. No. WO94/25875 PCT Pub. Date Nov. 10, 1994A fully functional analyzing unit is included within the fluid-tight housing of a dialyzer which may be immersed in the medium to be analyzed. An opening in the housing is closed by a dialysis membrane. A channel defining body cooperates with the membrane to define a flow channel. The unit includes a carrier fluid reservoir and a carrier pump for generating a flow of carrier fluid through the flow channel. By dialysis via the membrane, the flow of carrier fluid is transformed into a flow of sample fluid which is received in a reaction channel. Reagent fluid from at least one reagent reservoir is delivered to the reaction channel by at least one reagent pump, and a detecting device is coupled to the reaction channel for detecting a reaction product originating from a reaction between the reagent fluid and the sample fluid and for generating a corresponding detection signal. Effluent from the reaction channel is received in a waste reservoir. Average volume flow in the reaction channel during operation is less than 100 mu l/min, allowing for at least 30 days of uninterrupted operation. The device is suitable for in situ real-time measurement of plant nutrient salts in process waters of waste water treatment plants.