Classification of workplace gases using temperature modulation of two SnO2 sensing films on substrate

Two SnO2-based sensing films (pure SnO2 and SnO2/Pt) and a Pt thin film as a temperature sensor were fabricated on an alumina substrate for classifying workplace environmental gases. By controlling the heating power in the shape of a trapezoid, a temperature profile of the SnO2 sensing films was created along with four unique sensing response curves to the tested gases. A principal component analysis (PCA) was performed using variables extracted from the sensing response curves. The results confirmed that the sensor array with the proposed operating mode was extremely effective in classifying workplace environmental gases, such as CO2, C3H8, and C4H10.