Abstract: An electrochemical analysis system includes a plurality of flow through analysis chambers and a valve connected in series between the outlet port of one analysis chamber and the inlet port of a second analysis chamber and has a first position connecting the two analysis chambers in series for flow of a sample to be analyzed therethrough and a second position in which the two analysis chambers are connected to separate sources of calibrating fluids. The valve includes a housing member with a recess in which a valve spool member is disposed. The spool member includes an array of ports in its cylindrical surface, two ports being interconnected by a through passage, and other ports being separately connected to individual sources of calibrating fluids.

Abstract: A replaceable cartridge assembly for use with electrochemical analysis apparatus includes a housing of electrically insulating material that defines an annular electrolyte chamber with coupling structure at one end of the housing and a chamber port at the other end of the housing. A selectively permeable membrane extends across the port in sealing relation thereto. An elongated guide channel within the housing is surrounded by the electrolyte chamber and receives a cooperating connector stem that carries a socket-temperature sensor assembly. A cathode electrode projects coaxially upwardly from the end wall of the guide channel into the stem socket and the lower portion of the cathode electrode extends through the guide channel end wall such that its tip is exposed to the membrane. An anode electrode is disposed in the electrolyte chamber with an external contact surface adjacent the coupling structure.