Detection and determination of harmful gases in confined spaces for the Internet of Things based on cataluminescence sensor

Gaseous cataluminescence (CTL) sensor instrument was developed for detecting and measuring pernicious gases such as ethyl ether, acetone, n-hexane, chloroform by using aluminum/iron oxides composites. The materials synthesis, apparatus and software, optimal conditions (flow rate, wavelength, temperature and concentration), selectivity and stability were thoroughly studied. The results indicated the CTL sensor instrument could response to ethyl ether under 180 degrees C, which was lower than most of the reported CTL reaction temperatures. In addition, the results showed that the linear detection range was wide, ranging from 10 ppm to 5800 ppm (R = 0.9978, n = 7), and the detection limit was also low (4.3 ppm). Moreover, for ethyl ether detection, the CTL sensor showed the response time of 4 s and recovery time of 8 s, which was relatively short. The pattern recognition methods included PCA, KPCA were selected for evaluating the recognition performance of this CTL sensor, results showed the analytes could be classified clearly. The low reaction temperature, excellent sensitivity, selectivity, stability and recognition performance indicated this CTL sensor was ideal for gas contaminants detection in confined spaces for the Internet of Things.