Pilot line manufactured custom quartz tuning forks (QTFs) with a resonance frequency of 28 kHz and a Q value of >30, 000 in a vacuum and ∼ 7500 in the air, were designed and produced for trace gas sensing based on quartz enhanced photoacoustic spectroscopy (QEPAS). The pilot line was able to produce hundreds of low-frequency custom QTFs with small frequency shift < 10 ppm, benefiting the detecting of molecules with slow vibrational-translational (V-T) relaxation rates. An Au film with a thickness of 600 nm were deposited on both sides of QTF to enhance the piezoelectric charge collection efficiency and reduce the environmental electromagnetic noise. The laser focus position and modulation depth were optimized. With an integration time of 84 s, a normalized noise equivalent absorption (NNEA) coefficient of 1.7 × 10⁻⁸ cm^-1∙W∙Hz^-1/2 was achieved which is ∼10 times higher than a commercially available QTF with a resonance frequency of 32 kHz.

中试生产线制造的定制石英音叉 (QTF) 的谐振频率为 28 kHz，Q 值在真空中 >30, 000，在空气中 ∼ 7500，设计和生产用于基于石英增强光声光谱的痕量气体传感（QEPAS）。该中试线能够生产数百个频移小于 10 ppm 的低频定制 QTF，有利于检测振动平移 (VT) 弛豫率较慢的分子。在QTF两侧沉积厚度为600 nm的Au薄膜，以提高压电电荷收集效率并降低环境电磁噪声。优化了激光焦点位置和调制深度。积分时间为 84 s，归一化噪声等效吸收 (NNEA) 系数为 1.7 × 10 ^-8 cm ^-1 ∙W∙Hz ^-1/2 ，比商用谐振 QTF 高约 10 倍频率为32kHz。