Apparatus for measuring a chemical entity in a liquid

Claim 1

Apparatus for measuring or detecting a chemical entity in a liquid sample, said apparatus comprising a first module operationally connected to a second module, said first module comprising a flow passage for receiving at least one liquid sample and having reagent containing means, of sufficient size with sufficient reagent to mix with a plurality of samples entering said flow passage to allow for succesive analysis of a plurlaity of samples, and having flushing fluid containing means said flow passage including a sensor section including sensor means for contacting fluid comprising a liquid sample and reagent to measure or detect a chemical entity of the fluid while establishing a noncontaminating relationship with said second module and said first module including pump means for advancing the sample along said flow passage and actuating said flushing fluid containing means, thereby flushing said first module between analysis of successive samples, said second module comprising means for actuating said pump means, said second module being connected to said first module via connecting means permitting disconnection of said first module from said second module and connection of a replacement first module to said second module, and wherein first module is in the form of a sealed disposable cartridge.