Rapid measurements and mapping of tracer gas concentrations in a large indoor space

被引：22

作者：

Fischer, ML ^{[1
]}

Price, PN ^{[1
]}

Thatcher, TL ^{[1
]}

Schwalbe, CA ^{[1
]}

Craig, MJ ^{[1
]}

Wood, EE ^{[1
]}

Sextro, RG ^{[1
]}

Gadgil, AJ ^{[1
]}

机构：

[1] Ernest Orlando Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Indoor Environm Dept, Berkeley, CA 94720 USA

来源：

ATMOSPHERIC ENVIRONMENT | 2001年 / 35卷 / 16期

基金：

美国国家卫生研究院; 美国国家航空航天局;

关键词：

tracer gas measurement; optical remote sensing; computed tomography; air flow;

D O I：

10.1016/S1352-2310(01)00081-4

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Rapid mapping of gas concentrations in air benefits studies of atmospheric phenomena ranging from pollutant dispersion to surface layer meteorology. Here we demonstrate a technique that combines multiple-open-path tunable-diode-laser spectroscopy and computed tomography to map tracer gas concentrations with approximately 0.5 m spatial and 7 s temporal resolution. Releasing CH4 as a tracer gas in a large (7 m x 9 m x 11 m high) ventilated chamber, we measured path-integrated CH4 concentrations over a planar array of 28 "long" (2-10m) optical paths, recording a complete sequence of measurements every 7 a during the course of hour-long experiments. Maps of CH, concentration were reconstructed from the long path data using a computed tomography algorithm that employed simulated annealing to search for a best fit solution. The reconstructed maps were compared with simultaneous measurements from 25 "short" (0.5m) optical paths located in the same measurement plane. On average, the reconstructed maps capture similar to 74% of the variance in the short path measurements. The accuracy of the reconstructed maps is limited, in large part, by the number of optical paths and the time required for the measurement. Straightforward enhancements to the instrumentation will allow rapid mapping of three-dimensional gas concentrations in indoor and outdoor air, with sub-second temporal resolution. (C) 2001 Elsevier Science Ltd. All rights reserved.

引用

页码：2837 / 2844

页数：8

共 15 条

[1] MIXING OF A POINT-SOURCE POLLUTANT BY NATURAL-CONVECTION FLOW WITHIN A ROOM [J].