Influence of the test-chamber shape on the performance of conductometric gas sensors

In this article, CFD simulations results are presented as a key tool to the comprehension of the target gas con- \ncentration evolution in a test chamber, at different working conditions. The simulation results are compared with the experimental data, which shows a qualitative good correlation with the evolution of the concentration \ngradient detected. The experiments were carried out using an aluminum gas test chamber, where a WO3 based \nconductometric sensor is introduced. The results demonstrate how the response time is dependent on the sensor \nworking conditions. Analyzing the CFD and experimental results, some assumptions for this behavior are \nproposed. \nThe WO3 sensor needs a Pt heating element, which is heated up to 300 ◦C. As the response is highly \ntemperature-dependent, the temperature distribution on the sensor surface was measured by an IR thermo- \ngraphic camera. The simulation results show that the temperature distribution matches with those obtained \nexperimentally. To validate the model, a mesh and time step convergence study was also implemented