Abstract
The carbon dioxide recorder here described is based on the variation in concentration of the bicarbonate salt in equilibrium with a saturated solution of the carbonate of an alkaline earth, preferably barium. The bicarbonate concentration is dependent upon the carbon dioxide partial pressure in the gas passed through the solution, and is measured by determining the electrolytic conductance of the solution. By using a recording A.C. milliammeter to measure this conductance a continuous record is obtained of the carbon dioxide in the gas.
The readings of the instrument are independent of the gaseous constituents other than carbon dioxide. It can therefore be used when other recorders are inapplicable owing to the simultaneous variation of several constituents of the gas to be analysed.