METHOD AND APPARATUS FOR LIQUID PHASE CALIBRATION OF OXYGEN AND CARBON DIOXIDE PARTIAL PRESSURE

A pre-determined amount of solubilized reagent is reacted to release CO2 in a controlled-temperature reaction vessel and a controlled-pressure area adjacent the reaction vessel. The devices that enable the system to be maintained in the liquid phase, and the reaction vessel itself, are controlled, assuming that the O2 in the solution is such as that deriving from the presence of O2 in the atmosphere, if necessary corrected for the effect of the reaction producing CO2. Thus, the amount of reagent taking part in the reaction being known, either by assay or by controlling the reaction time, by controlling the amount of O2 in the solution containing the reagent, the barometric pressure, the temperature in the reaction vessel, and the coefficients of solubility of the two gases, it becomes possible to predict the partial pressures of O2 and CO2 in the liquid phase produced, which liquid phase is suitable for use as a calibration substance for an apparatus for measuring blood gases.