Kukhtin S. Modulation laser spectroscopy of methane in air and water

The object – process of methane measurement. The goal – theoretical and experimental research of modulation laser spectroscopy method for registration of methane gas mixtures in wide range of absorptions, evaluation of the possibility of dissolved methane detection by means of modulation laser spectroscopy. Methods – mathematical modelling, mathematical physics, experimental research and measurements processing. Results – mathematical model for modulation laser spectroscopy has been developed that accounts arbitrary absorption values of laser radiation and amplitude-frequency characteristics of distributed feedback laser diodes. Method of laser frequency tuning on the maximum of an absorption which provides best measurement accuracy has been appraised. Methodological errors for modulation laser spectroscopy method were evaluated. Method of modulation laser spectroscopy for detection of methane in water received further development. Field of application – spectroscopy of gasses, gas trace detection.