Characterization of sensing chamber design for E-nose applications

Abstract

An electronic nose (e-nose) is a device that mimics the function of the human nose and is able to recognize odours using gas sensors. The e-nose consists of a sampling system, a sensor array (in the detection system), with data acquisition and pattern recognition algorithm for computing system. The sensing chamber in an e-nose plays an important role in the detection system for any types of application. The design of the sensing chambers will determine several performance characteristics of the sensor's response signals which include the response time, stagnant region and gas to the sensor contact area. Several sensing chambers (rectangular, hemisphere & cylindrical) were designed using SolidWorks and printed (in 3-dimensional (3D)) to characterize and determine the design which is able to provide the optimum performance. Data analysis of the response time and parameters such as concentration and pressure were analyzed using NI LabView. Results show that the hemisphere shaped sensing chamber displayed the best performance in terms of a small stagnant region and a large gas to the sensor contact area even though the time response between sensing chambers is almost the same. The performance was due to the flow of the gas from the inlet to the outlet and the volume of the sensing chamber.