ABG Analyzers Directly measures - Severinghaus, - Clark, pH - HCO3, SaO2 and other values are calculated Formula for read out: (Barometric Pressure - ) x Fractional Concentration of
Severinhaus Electrode Measures electrode in jacket Includes nylon spacer and membrane
PCO2 Calibration: Cylinders containing known concentrations of gas: Low: % balance High: % slope
Clark Electrode Measures Platinum cathode, silver-silver chloride anode, polypropolene membrane (gas ) Using membrane results in insufficient O2 diffusion Cleaning top with periodically to clean
PO2 Calibration: Cylinders containing known concentrations of gas: Low: % balance High: % or % slope
Sanz Electrode Measures PH Reference Electrode Contains: solution with known PH, has contsant potential. Measuring electrode contains: Solution, silver-silver chloride wire and pH sensitive glass capillary tube Introduction of sample causes electrical to develop. Voltage difference is proportional to PH
Sanz Electrode Calibration: Low pH solution: - If displayed value is different than the known sample, adjust with the to known value. High pH solution: - If displayed value is different than the known sample, adjust with the control to known value.
Tonomotry Used for quality with ABG analyzers Allows precise gas mixtures to be with buffer solution or whole blood samples Best method for precise control of electrode Vert complex - not widely used
