Monitoring of toxic industrial chemicals with low power consumption sensor arrays

The scope of the thesis is to investigate, the concentrations of toxic industrial chemicals that have been measured using various gas sensor modules. Short-term exposure concentrations were considered as references when planning to determine the test concentrations and all measurements have been carried out in the ranges of these reference values. Electrochemical gas sensors were used for the meausurements and the measured data were transferred from the sensor test cells to an Arduino-based mikrocontroller unit via wired connection and monitored. The test studies were carried out in TIC Sensor Test Laboratory of TÜBİTAK MAM CBRN Defense Technologies Research Group verify the operation of the designed system and to collect data using it. In the testing process, the responses of the sensors to NH3, NO2, AsH3, CO, CO2, SO2 gases were evaluated. Sensor outcomes were described based on the calibration curves that were plotted using the data extracted from the sensor responses. In addition, the humidity characteristics of the sensors were analyzed. Responses of the sensors to gases at different time and humidity rates were measured. The responses were determined and characterized under 50% and 85% relative humidity conditions. Principle component analyzes were performed by using the varying responses of the developed sensor test cell to these gases. After PCA, it was concluded that toxic chemical gases were completely separated from each other in 50% and 85% humid environments. Keywords; toxic industrial chemicals, chemical sensors, microcontroller, data processing, principal components analysis (PCA)