A compact QCL based methane and nitrous oxide sensor for environmental and medical applications

Abstract

A methane (CH4) and nitrous oxide (N2O) sensor based on a sensitive, selective and well established technique of quartz enhanced photoacoustic spectroscopy (QEPAS) was developed for environmental and biomedical measurements. A thermoelectrically cooled (TEC) distributed feedback quantum cascade laser (DFB-QCL), capable of continuous wave (CW) mode hop free emission in the 7.83 μm wavelength range, was used as an excitation source. For the targeted CH4 and N2O absorption lines located at 1275.04 cm(-1) and 1275.49 cm(-1) detection limits (1σ) of 13 ppbv and 6 ppbv were achieved with a 1 second data acquisition time, respectively. Environmental data of CH4 and N2O mixing ratios acquired using the QEPAS sensor system are also reported.

Highly sensitive detection of methane by near-infrared laser absorption spectroscopy using a compact dense-pattern multipass cell

“…Laser absorption spectroscopy based techniques offer the unique advantages for fast, self-calibration, highly selective and highly sensitive in situ quantification of CH 4 without any sample preparation [8][9][10][11][12][13][14]. Based on the Beer-Lambert absorption law, the detection sensitivity by absorption spectroscopy is proportional to the molecule absorption path length and the molecule absorption line intensity.…”

Лазерная Генерация Многопериодных Квантово-Каскадных Лазеров На Длине Волны Излучения 8 Мкм При Комнатной Температуре

“…Более того, присутствие СH 4 в выдыхаемом человеком воздухе свидетельствует о ряде заболеваний желудочно-кишечного тракта (син-дром раздраженного кишечника, рак толстой кишки, за-труднение дефекации [6,7]). Помимо технологии газоана-лиза выдыхаемого воздуха, также представляет интерес детектирование различных жидкостей при осаждении на поверхность ККЛ (геометрия ККЛ с воздушной верхней обкладкой [8]).…”

Portable Laser Photoacoustic Methane Sensor Based on FPGA

“…Methane (CH4) detection plays an important role in various applications, such as natural gas exploration, coal mining, medical diagnostics and environment monitoring [1][2][3][4][5]. There exist numerous CH4 sensing devices based on different detection principles like catalytic combustion, gas chromatography (GC), electrochemical sensors, semiconductor, infrared spectroscopy, etc [6][7][8].…”