Development of Multichannel Data Acquisition System for Metal Oxide Sensor Array as an Electronic Nose

The multichannel data acquisition system is developed for the measurement of the resistance of metal oxide sensor array response for electronic nose application. The resistance of the sensor varies with the concentration of analytes. The instrumentation is developed in-house which measures the output of sensor array and sends the data to the PC through LAN. The data acquisition software was developed for four channels to collect the data in PC in the form of counts and converts it into the resistance of sensors by using a suitable algebraic equation. Principal Component Analysis was implemented in the software to discriminate the analytes. The software is equipped with user-friendly features like online monitoring, on-demand pop-up window to check the overall trend of sensor behavior for a larger data etc. The data are stored with the time stamp in a file for post analysis. The data acquisition software was tested with various standard resistors and found the results were good. Further, the data acquisition software was also tested with the sensor and logged the sensor data for the study of sensors. The features of this development and the results obtained from the experiments are described in this paper.