Hydrogen sensing behavior of SnO2 and in2O3 thin films in wide range of humid conditions – An exploratory data analysis

Abstract Effect of humidity varied from 20 % to 95 % RH on thin film gas sensors of SnO2 and In2O3, operated at 623 K are presented. The sensitivity of SnO2 sensor is independent of humidity varied from 20 % to 95 % RH for 10–100 ppm of H2 whereas, In2O3 exhibited a differential sensitivity. The principal component analysis (PCA) of various features of the response curve results in selective features responsible for the distribution of the sensor’s signal in different humidity ambiences. The subtle changes in the sensitivity profiles of In2O3 along with the feature analysis can provide a different approach for the estimation of humidity in ambience along with the hydrogen. Sensors made of SnO2 can operate in highly humid conditions and found suitable for industrial application for sensing hydrogen from 10 to 100 ppm.