Field methane tracking with a portable and real-time open-gas monitor based on a cw-driven Pb-salt diode laser

R. Koga, Megumi Kosaka, H. Sano

Research output: Contribution to journalArticle

9 Citations (Scopus)


An atmospheric gas monitor with a PbSnTe diode laser has been developed. The open, 1 m optical path in a single-folded configuration enables local and non-contact measurement in a portable instrument. The accuracy is dependent on optical noise and a technique in diode-current modulation was effective in suppressing it. Analysis of the system noise based on the experimental data was made and a 10 ms interval was sufficient to attain an accuracy of 3 ppm for methane. Field measurements were made and a rapid fluctuation in the density of atmospheric methane density was recorded.

Original languageEnglish
Pages (from-to)139-144
Number of pages6
JournalOptics and Laser Technology
Issue number3
Publication statusPublished - 1985



  • gas concentration measurement
  • methane
  • optical equipment

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics

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