Abstract: A combination pH and CO.sub.2 sensor employs separate sensors. Each sensor has a wire with an electrochemically active layer, an electrolyte layer and a membrane between the electrolyte layer and the fluid to be tested. Each electrolyte layer is constructed of a dried residue which can be easily stored and which must be rehydrated prior to the first use. The electrolyte layer in the pH sensor when hydrated forms an aqueous solution buffered against changes in pH due to changes in the dissolved CO.sub.2 concentration and is preferably formed of 2-(n-morpholino) ethanesulfonic acid, 2-(n-morpholino) ethanesulfonic acid - sodium salt and potassium chloride. The electrolyte layer in the CO.sub.2 sensor when hydrated forms an aqueous solution having bicarbonate ions and is preferably formed of polyvinyl alcohol, sodium chloride and sodium bicarbonate. The electrical potential at the pH sensor is proportional to the pH of the fluid. The electrical potential difference between the CO.sub.

Abstract: A clinical chemistry analyzer system for blood chemistry analysis is disclosed. Two major parts comprise the system. One part is a discardable sensor cartridge which contains a bank of sensors, calibration fluid containers, conduit means and an external peristallically pumpable tube section. The other part is an analysis machine which interfaces with the discardable cartridge and has means to drive the peristaltic pump as well as means to interface with the sensors of the cartridge to provide a readout therefrom. The system is adapted to be made part of a heart/lung machine sustaining a patient in order to sample and monitor the venous and arterial blood flow thereof.

Abstract: This invention relates to solid-state electrode or micro-electrode sensor apparatus for measuring certain characteristics of an aqueous sample such as a body fluid or a blood sample and more particularly to such apparatus which employs a disposable cartridge containing a sensor or a bank of sensors for such characteristics and reagents used to calibrate the sensors.