Patent ID: 8881580

Claim:
A process analysis unit for the determination of an analyte in water, the process analysis unit comprising a base module and an exchangeable cartridge module which is configured to be connected to the base module, the base module comprising: at least one independent pump drive, and an analyte sensor without a fluidic measuring section, wherein the base module does not comprise a liquid fluidic system; and the cartridge module comprising the liquid fluidic system, the cartridge module comprising: a liquid reservoir tank, a sample taking device, at least one drive-less pump mechanism configured as a peristaltic membrane pump, the drive-less pump mechanism being configured to be driven pneumatically and to pump a liquid from the liquid reservoir tank, wherein the peristaltic membrane pump comprises pump chambers covered by a flexible liquid-tight pump membrane, a fluidic measuring section for the analyte sensor, and a plastic material plate with groove-like microfluidic channels configured to connect the liquid reservoir tank, the at least one drive-less pump mechanism, and a measuring section, a section of the groove-like microfluidic channels being less than 5 mm 2 , wherein, when the cartridge module is connected to the base module, the at least one drive-less pump mechanism is connected to and is driven by the at least one independent pump drive, and the fluidic measuring section is connected to the analyte sensor, and each of a plurality of the at least one drive-less pump mechanism is associated with a respective at least one independent pump drive.