Conductometric determination of CO2 in air samples

A new procedure enables the CO2 concentrations of air samples to be determined and automatically registered. The CO2 contents of the air samples are absorbed in an Sr(OH)2 solution. The resulting decrease in electrical conductivity of the solution is automatically registered by a d.c. strip-chart recorder in such a way that the decline of the curve is proportional to the amount of CO2 absorbed. In each analysis, quantities of CO2 up to about 8 mumol can be determined with an error of less than 0.02 mumol, and, accordingly, CO2 quantities of 2 to 8 mumol contained in samples of at least 150 ml of fresh atmospheric air or about 1 ml of carboxygen or expired air can be analysed with an accuracy of better than +/- 1.0% of their CO2 content.