Lorenz Curve-Based Temperature Drift Compensation in Photoacoustic Spectroscopy Gas Detection

We propose a brand-new temperature drift compensation method based on Lorentz curve to reduce the influence of temperature drift on the detection of trace gases in photoacoustic (PA) spectroscopy. A new interesting feature is observed that the amplitude of PA signal shows a Lorentzian distribution centered at the resonance frequency of the PA cell. Based on this phenomenon and the reported relationship between temperature and resonant frequency, we innovatively propose a Lorenz curve-based temperature drift compensation method in PA spectroscopy, which is particularly suitable for trace gases detection. In a proof-of-concept experiment, when the temperature varies in the range from 295 to 307 K, the maximum measurement errors for acetylene gas at concentrations of 0.8 and 0.2 ppm are, respectively, 0.05 and 0.03 ppm, which are more than 20 times smaller than that of other temperature drift compensation methods. The proposed method may provide a new promising approach to realize trace gases detection in a temperature varying environment.