A system for detection of ethylene (C₂H₄) at high pressure is developed based on tunable diode laser absorption spectroscopy using a distributed feedback laser near 1620 nm. To eliminate the influence of spectral line overlap under high pressure, a differential absorption (peak-minus-valley) scheme is adopted. The peak and valley wavelengths used for the measurement correspond to 6174.64 and 6174.45 cm^–1, respectively. Absorption cross sections of ethylene are measured for the selected peak and valley wavelengths. The measured concentration agrees with the known concentration, and the maximum of the standard deviation is 0.746% for all measurements. In addition, long-term continuous measurements indicated good stability of the system. The sensitivity of the system is ~18 ppm with an optimum averaging time of 110 s. All the experimental results validate the applicability of the system in ethylene trace detection.

基于可调谐二极管激光吸收光谱技术，使用1620 nm附近的分布式反馈激光，开发了一种高压下的乙烯（C ₂ H ₄）检测系统。为了消除高压下光谱线重叠的影响，采用了差分吸收（峰-谷）方案。用于测量的峰值和谷值波长对应于6174.64和6174.45 cm ^–1， 分别。对于选定的峰值和谷值波长，测量乙烯的吸收截面。测得的浓度与已知浓度一致，所有测量的标准偏差最大值为0.746％。此外，长期连续测量表明系统具有良好的稳定性。系统的灵敏度为〜18 ppm，最佳平均时间为110 s。所有的实验结果验证了该系统在乙烯痕量检测中的适用性。