基于可调谐激光吸收光谱技术的硫化氢检测方法研究

硫化氢气体在线监测对于控制其泄漏风险、保护环境十分重要。可调谐激光吸收光谱技术具有灵敏度高,速度快,特异性强等优点,在气体在线检测领域具有十分广阔的应用前景。研究了基于可调谐激光吸收光谱技术的硫化氢气体检测方法,及针对测量条件变化的校正方法。测量系统采用温度与电流调谐两种方式,不仅扩展了调谐范围,并且保证了调谐速率与稳定性,在锁相检测技术基础上,实现了气体吸收信号二次谐波分量提取。分析了气体压力与温度对于吸收光谱测量影响,提出了基于参数拟合的校正方法。实验结果表明,所研究的检测系统可实现硫化氢气体高灵敏检测,校正方法可有效消气体温度、压力等条件变化对于建模预测结果的影响。

Research on hydrogen sulfide detection based on tunable laser absorption spectroscopy

Monitoring hydrogen sulfide is very important for controlling the risk of leakage and protecting the environment safety. Tunable diode laser absorption spectroscopy, which takes the advantages of high sensitivity, speed and specificity, has a very broad application prospect in the field of gas on line detection. In this paper, the hydrogen sulfide gas detection method is proposed based on tunable laser absorption spectroscopy and the calibration method to eliminate the effect of pressure and temperature. The measuring system applies both temperature and current tuning protocol to achieve larger tuning range, higher tuning speed and stability. Based on the lock in technology, the second harmonic are extraction from the absorption signal of hydrogen sulfide. By analyzing the influence of gas pressure and temperature on the absorption spectrum, the calibration method based on parameter fitting is proposed. The results show that the detection system achieves high sensitivity in hydrogen sulfide detection. The calibration method is effective in eliminating the influence of gas temperature and pressure.