Wang Zhen, Du Yan-Jun, Ding Yan-Jun, Lü Jun-Fu, Peng Zhi-Min. Wide-range and calibration-free H2S volume fraction measurement based on combination of wavelength modulation and direct absorption spectroscopy with cavity ringdown spectroscopyJ. Acta Physica Sinica, 2022, 71(18): 184205. DOI: 10.7498/aps.71.20220742