Comb-assisted cavity ring-down spectroscopy for ultra-sensitive traceable measurements of water vapour in ultra-high purity gases. Issue 1 (1st January 2023)

• Record Type: Journal Article
• Authors: Fasci, E; D'Agostino, V; Khan, M A; Gravina, S; Porzio, G; Gianfrani, L; Castrillo, A
• Is Part Of: Journal of physics. Volume 2439:Issue 1(2023)
• Publication Date: 2023-01-01
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/2439/1/012017
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: We report on the development of a comb-assisted cavity ring-down spectrometer for trace water mole fraction determinations in high purity gases. By tuning the laser light in coincidence with a H2 O absorption line at 1.3946 µ m, we were able to determine sub-ppm relative concentrations of water vapour in N2 with a sub-percent statistical uncertainty. The sensitivity of the spectrometer was carefully assessed, yielding a detection limit of about 2 nmol/mol.