We demonstrated that quartz-enhanced photoacoustic spectroscopy (QEPAS) is an efficient tool to measure the vibrational relaxation rate of gas species, employing quartz tuning forks (QTFs) as sound detectors. Based on the dependence of the QTF resonance frequency on the resonator geometry, a wide range of acoustic frequencies with narrow detection bandwidth was probed. By measuring the QEPAS signal of the target analyte as well as the resonance properties of different QTFs as a function of the gas pressure, the relaxation time can be retrieved. This approach has been tested in the near infrared range by measuring the CH₄ (nν₄) vibrational relaxation rate in a mixture of 1% CH₄, 0.15 % H₂O in N₂, and the H₂O (ν₁) relaxation rate in a mixture of 0.5 % H₂O in N₂. Relaxation times of 3.2 ms Torr and 0.25 ms Torr were estimated for CH₄ and H₂O, respectively, in excellent agreement with values reported in literature.

我们证明，采用石英音叉（QTF）作为声音检测器，石英增强型光声光谱法（QEPAS）是测量气体种类振动弛豫率的有效工具。基于QTF谐振频率对谐振器几何形状的依赖性，探测了具有窄检测带宽的宽范围的声频率。通过测量目标分析物的QEPAS信号以及不同QTF的共振特性作为气压的函数，可以获取弛豫时间。这种方法已在近红外范围内，通过测量CH被测试₄（nν ₄）振动弛豫率在1％CH的混合物₄，0.15％H ₂在N 2 O ₂和H ₂ O（ν ₁）松弛在0.5％H的混合物速率₂ ö的N ₂。CH ₄和H ₂ O的弛豫时间分别为3.2 ms Torr和0.25 ms Torr ，与文献报道的值非常吻合。