Semiconductor gas sensors measuring system accuracy improvement with thermostimulated electrical conductance approach

Volatile organic compounds (VOCs) are a major group of air pollutants. They exist in the atmosphere as vapors. Because of the complexity of the VOC mixtures, sophisticated analytical methods are required to distinguish one compound from another. There is a great deal of interest in the development of relatively cheap and simple instruments for the continuous, in-situ and real time measurements. The semiconductor sensor systems provide a very interesting solution in this field of research. In this paper the attention was paid how to examine influence of measuring methods to analyze accuracy. Two different measuring methods were tested: simple response and thermostimulated electrical conductivity, their influence on precision of quantitative analyses were investigated. The results obtained with the thermostimulated electrical conductance measurements outperformed the traditional systems based on simple responses of thick film gas sensors matrices.