Patent ID: 8383046

Claim:
Analyzer apparatus for measuring amounts of at least one specific analyte dissolved in a liquid external to the analyzer apparatus comprising: a measurement cavity block defining a measurement cavity and an analyte inlet, the analyte inlet having one side in communication with the measurement cavity and an opposed side positionable to communicate with the specific analyte dissolved in the liquid; an analyte sensor and sensor assembly, the analyte sensor selected to sense the at least one specific analyte and sensitive only to the at least one specific analyte to provide a determination of analyte amount without interference from other substances, the analyte sensor assembly including an infrared radiator and infrared sensor pair; the analyte sensor assembly sealingly affixed to the block with the analyte sensor in communication with the measurement cavity, the sensor assembly sealing the measurement cavity from environment outside the measurement cavity with the infrared radiator mounted to radiate infrared through the measurement cavity to the infrared sensor; and a semipermeable membrane affixed to the measurement cavity block over the analyte inlet and constructed to allow the at least one specific analyte to pass through the membrane into the measurement cavity while restricting the liquid from flowing into the cavity, the measurement cavity being sealed from environment outside the measurement cavity except for analyte entering the measurement cavity through the semipermeable membrane, whereby the analyte sensor senses only the at least one specific analyte without the introduction of any other substance.