Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

doi:10.2172/1044815

GSTDTAP > 地球科学

DOI	10.2172/1044815
报告编号	DOE/10SC000316
来源ID	OSTI ID: 1044815
	Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer
	Xu, Liukang [LI-COR Inc., Lincoln, NE (United States)]; McDermitt, Dayle [LI-COR Inc., Lincoln, NE (United States)]; Anderson, Tyler [LI-COR Inc., Lincoln, NE (United States)]; Riensche, Brad [LI-COR Inc., Lincoln, NE (United States)]; Komissarov, Anatoly [LI-COR Inc., Lincoln, NE (United States)]; Howe, Julie [LI-COR Inc., Lincoln, NE (United States)]
	2012-02-01
出版年	2012
页数	50
语种	英语
国家	美国
领域	地球科学
英文摘要	Robust, economical, low-power and reliable closed-path methane (CH₄), carbon dioxide (CO₂), and water vapor (H₂O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH₄ and CO₂ released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO₂ budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been utilized to randomize the noise introduced from potential etalons. It is expected that all original specifications contained within the initial proposal will be met. We are currently in the beginning stages of assembling the first generation prototypes and finalizing the remaining design elements. The first prototypes will initially be tested in our environmental calibration chamber in which specific gas concentrations, temperature and humidity levels can be controlled. Once operation in this controlled setting is verified, the prototypes will be deployed at LI-COR's Experimental Research Station (LERS). Deployment at the LERS site will test the instrument's robustness in a real-world situation.
英文关键词	Closed-path methane analyzer closed-path water vapor gas analyzer
URL	查看原文
来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/5698
专题	地球科学
推荐引用方式 GB/T 7714	Xu, Liukang [LI-COR Inc., Lincoln, NE ,McDermitt, Dayle [LI-COR Inc., Lincoln, NE ,Anderson, Tyler [LI-COR Inc., Lincoln, NE ,et al. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer,2012.