Temperature-dependent characteristics of a photoacoustic detector

A detailed study on the temperature dependent characteristics of a wavelength modulated diode laser based photoacoustic (PA) detection system is presented. The temperature stability of the PA system and the temperature dependence of the resonance frequency, Q-factor, and cell constant of the resonator are investigated. The variation relationship between the cell constant and the Q-factor is compared with the changes of temperatures. The measurement of the system sensitivity shows that the PA system can be used to test trace gases in the upper troposphere and lower stratosphere. It provides the theoretical and experimental basis for the design of low temperature PA system.