SEMICONDUCTOR GAS SENSORS AND PROBLEMS OF THE EARTHS OZONOSPHERE

One of the modern problems in the physical chemistry of the Earth's at mosphere is that of the stratospheric ozone, its variation and the pos sibilities of its destruction. The processes leading to ozone-layer ex haustion are essentially at altitudes up to 100 kn. Their description and forecasting are not possible without precise measurement of the co ncentrations of ozone and some other small components of the atmospher e that affect the ozone regime. Such measurements are also necessary f or the investigation of the atmospheric effects of stratospheric super sonic aviation flights. The existing measurement methods (electrochemi cal or chemoluminescent types of ozone sensors, resonant fluorescent s pectroscopic analysers) are not always adequate for contemporary requi rements. In this communication the possibilities of using chemical sen sors based on semiconductor metal oxides are considered. These sensors offer the opportunity of measurement of both the ozone and a series o f other small components of the ozonosphere (OH, Cl, Cl-2, O-1(2), and others). The experimental peculiarities of obtaining and detecting so me of the above-mentioned particles and the possibilities of selective ly distinguishing the useful signal are discussed. Semiconductor chemi cal sensors, because of their characteristic high sensitivity (10(4)-1 0(6) cm(-3)), fast-action (<1 s) and simplicity of signal transformati on, are very promising for use on flying devices such as spaceships, r ockets and balloons. As an example, a flying atomic oxygen analyser ha s been developed and successfully used for atmospheric investigations.