Impact of Humidity on Quartz-Enhanced Photoacoustic Spectroscopy Based CO Detection Using a Near-IR Telecommunication Diode Laser
نویسندگان
چکیده
A near-IR CO trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is evaluated using humidified nitrogen samples. Relaxation processes in the CO-N2-H2O system are investigated. A simple kinetic model is used to predict the sensor performance at different gas pressures. The results show that CO has a ~3 and ~5 times slower relaxation time constant than CH4 and HCN, respectively, under dry conditions. However, with the presence of water, its relaxation time constant can be improved by three orders of magnitude. The experimentally determined normalized detection sensitivity for CO in humid gas is 1.556 × 10(-8) W ⋅ cm (-1)/Hz(1/2).
منابع مشابه
Ammonia detection by use of quartz-enhanced photoacoustic spectroscopy with a near-IR telecommunication diode laser.
A gas sensor based on quartz-enhanced photoacoustic detection and a fiber-coupled telecommunication distributed-feedback diode laser was designed and characterized for trace NH3 monitoring at a 1.53-microm wavelength (overtone absorption region). Signal and noise dependence on gas pressure were studied to optimize sensor performance. The ammonia concentration resulting in a noise-equivalent sig...
متن کاملInfluence of molecular relaxation dynamics on quartz - enhanced photoacoustic detection of CO 2 at λ = 2 μ
Carbon dioxide (CO 2) trace gas detection based on quartz enhanced photoacoustic spectroscopy (QEPAS) using a distributed feedback diode laser operating at λ = 2 µm is performed, with a primary purpose of studying vibrational relaxation processes in the CO 2-N 2-H 2 O system. A simple model is developed and used to explain the experimentally observed dependence of amplitude and phase of the pho...
متن کاملDetection of Molecular Oxygen at Low Concentrations Using Quartz Enhanced Photoacoustic Spectroscopy
Molecular oxygen is detected at low concentrations using photoacoustic spectroscopy despite its unfavorable photoacoustic properties. The system consists of a seed laser diode, a tapered amplifier and a quartz tuning fork based spectrophone, thus employing quartz enhanced photoacoustic spectroscopy (QEPAS). With this system a detection limit of 13 ppm is reached with a compact and long term sta...
متن کاملAdvanced quartz-enhanced photoacoustic trace gas sensor for early fire detection
A spectroscopic trace gas sensor using a distributed feedback diode laser at λ=1.53 μm and based on quartz enhanced photoacoustic spectroscopy technique is described. The sensor is capable of quasi-simultaneous quantification of trace ammonia, hydrogen cyanide, and acetylene (NH3, HCN, and C2H2, respectively) concentrations at ~100 ppbv levels with a 4s integration time. The sensor design, resp...
متن کاملCarbon dioxide and ammonia detection using 2 μ m diode laser based quartz - enhanced photoacoustic spectroscopy
Quartz-enhanced photoacoustic spectroscopy was employed for trace gas concentration measurements of CO 2 and NH 3 using a continuous wave thermoelectrically cooled, distributed feedback diode laser operating at 2 µm. A normalized noise equivalent absorptionvspace1pt coefficient, NNEA(1σ) = 1.4 × 10 −8 cm −1 W/ √ Hz was obtained for CO 2 using the R18 line of the 2ν 1 + ν 3 band at 4991.26 cm −1...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Sensors
دوره 16 2 شماره
صفحات -
تاریخ انتشار 2016