Investigating Temperature Effects on Resonant Photoacoustic Gas Sensor: Ring-Shaped Cell Case Study

Photoacoustic spectroscopy (PAS) has garnered significant attention in recent years as a highly effective method for gas sensing, particularly in detecting trace gases. However, its performance depends on environmental factors, such as temperature variations. This study delves into the impact of temperature fluctuations on the photoacoustic signal, focusing on a temperature range typical of indoor settings. Utilizing COMSOL software simulations and experimental validation, we investigate the impact of the variation of temperature during measurement process on the photoacoustic (PA) signal. This influence has been investigated considering also different target gases, including carbon monoxide (CO), nitrogen N 2 and ammonia (NH3). We consider the dependence of gas acoustic properties on temperature, specifically the speed of sound and density. Our analysis centers on a resonant PA cell with ring geometry, which was implemented by the authors for detecting low concentrations of nitrogen dioxide. The performed analysis and the observed results highlight the influence of temperature fluctuations on key parameters associated with the involved physical phenomena, also considering gas species with different molar masses and concentrations. The analysis allows the evaluation and quantification of various factors that contribute to reduced sensitivity and accuracy of gas measurement. Moreover, it provides a good starting point to the design of proper temperature compensation procedure and provides valuable insights for similar PA resonant gas sensor systems that depend on environmental conditions.