Ma Hanxu, Qiao Shunda, He Ying, Ma Yufei
National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin 150001, China.
Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou 450008, China.
Sensors (Basel). 2025 Feb 5;25(3):946. doi: 10.3390/s25030946.
A highly sensitive light-induced thermoelastic spectroscopy (LITES) sensor employing a charge amplifier (CA) is reported for the first time in this invited paper. CA has the merits of high input impedance and strong anti-interference ability. The usually used transimpedance amplifier (TA) and voltage amplifier (VA) were also studied under the same conditions for comparison. A standard commercial quartz tuning fork (QTF) with a resonant frequency of approximately 32.76 kHz was used as the photothermal signal transducer. Methane (CH) was used as the target gas in these sensors for performance verification. Compared to the TA-LITES sensor and VA-LITES sensor, the reported CA-LITES sensor shows improvements of 1.83 times and 5.28 times in the minimum detection limit (MDL), respectively. When compared to the LITES sensor without an amplifier (WA-LITES), the MDL has a 19.96-fold improvement. After further optimizing the gain of the CA, the MDL of the CA-LITES sensor was calculated as 2.42 ppm, which further improved the performance of the MDL by 30.3 times compared to the WA-LITES. Additionally, long-term stability is analyzed using Allan deviation analysis. When the average time of the sensor system is increased to 50 s, the MDL of the CA-LITES sensor system can be improved to 0.58 ppm.
在这篇特邀论文中首次报道了一种采用电荷放大器（CA）的高灵敏度光致热弹性光谱（LITES）传感器。电荷放大器具有高输入阻抗和强抗干扰能力的优点。在相同条件下还研究了通常使用的跨阻放大器（TA）和电压放大器（VA）以作比较。使用谐振频率约为32.76 kHz的标准商用石英音叉（QTF）作为光热信号传感器。在这些传感器中使用甲烷（CH₄）作为目标气体进行性能验证。与TA-LITES传感器和VA-LITES传感器相比，所报道的CA-LITES传感器在最低检测限（MDL）方面分别提高了1.83倍和5.28倍。与无放大器的LITES传感器（WA-LITES）相比，最低检测限提高了19.96倍。在进一步优化电荷放大器的增益后，CA-LITES传感器的最低检测限计算为2.42 ppm，与WA-LITES相比，最低检测限的性能进一步提高了30.3倍。此外，使用阿伦偏差分析对长期稳定性进行了分析。当传感器系统的平均时间增加到50 s时，CA-LITES传感器系统的最低检测限可提高到0.58 ppm。
