Accuracy and Etalon Fringe Phenomena in Methane-gas Spectrometry Employing Tunable Diode Lasers

• Koga Ryuji

• Nagase Satoru

• Kosaka Megumi

• Sano Hiroya

抄録

A method to monitor atmospheric gas concentration employing a tunable diode laser is proposed. An apparatus was built and experiments were made. The tunable diode laser employed was of'PbSnTe with its wavenumber about 1200 cm(-1) at a temperature of 77 K. Methane concentration in laboratory atmosphere was measured on the experiments. The inquired gas-density is obtained by a hardwired microcomputer incorporating the measured absorption spectrum over a prescribed range instead of an absorption at a single wavenumber. By this, drift type noises are suppressed. After an analysis based on experimental data, an attainable sensitivity for methane was found to be 1 ppb.m. This value may increase if an etalon fringe interference exists. The natural concentration, about 1 ppm, of atmospheric methane was actually measured with a short optical path of only one meter.

収録刊行物

• Memoirs of the School of Engineering, Okayama University

  Memoirs of the School of Engineering, Okayama University 15 (2), 79-92, 1981-03-30

  岡山大学工学部

詳細情報

• CRID: 1390572174510441344
• NII論文ID: 120002307246
• NII書誌ID: AA00733903
• ISSN: 04750071
• DOI: 10.18926/15776
• Web Site: https://ousar.lib.okayama-u.ac.jp/15776
• 本文言語コード: en
• データソース種別:
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  • CiNii Articles