Measuring complex for monitoring carbon dioxide in air

Abstract

The advantages and disadvantages of infrared and electrochemical gas analyzers for carbon dioxide CO₂ are described. The possibility of using conductometric sensors with distilled water for monitoring the CO₂ content in the air has been investigated. Two identical measuring systems were manufactured, each containing two open-type conductometric cells, a matching device and a personal computer. With the help of these complexes, experiments were carried out on the simultaneous measurement of the CO₂ content in the air in two places (a laboratory room and a building in a forest, located at a distance of 15 km from each other) with deliberately different daily dynamics of the CO₂ level change. A special experiment was carried out, which made it possible to obtain an estimate of the inertia of conductometric cells and a conversion factor for the values of CO₂ content into standard units of measurement. It is shown that the daily dynamics of changes in the electrical conductivity of distilled water in open cells corresponds to the expected dynamics of changes in the CO₂ content in the rooms where the measurements were carried out. The operability of the measuring complex and the possibility of creating on its basis a device for long-term monitoring of the CO₂ content in the air mixture of gases has been confi rmed. The principal high selectivity of the measuring complex to CO₂ in relation to other gases of the atmosphere has been established.