Temperature-dependent photoacoustic spectroscopy with a T shaped photoacoustic cell at low temperature

A homemade low-temperature, T shaped photoacoustic (PA) spectrometer is well established. The temperature stability and characteristics of the PA system in the temperature range of −90 to 0 °C were evaluated experimentally. A mathematical model for calculation of resonance frequencies and end-correction are proposed. The results of numerical calculations of the temperature dependent of resonant frequencies and the Q-factor of PA cell are compared with experimental measurements. The measured results show that the PA system has high Q-factor and the theoretical value is very well consistent with the experimental results. The variation of sensitivity of the PA system is very small in temperature range of −90 to 0 °C, which illustrates that the sensitivity of the microphone has little been affected by low temperature. So the system can be used in trace gas detection at low-temperature.