US EPA

972385 

Journal Article 

Hazardous gas detection using an integrating sphere as a multipass gas absorption cell 

Hawe, E; Fitzpatrick, C; Chambers, P; Dooly, G; Lewis, E 

2008 

1 

Sensors and Actuators A: Physical
ISSN: 0924-4247
EISSN: 1873-3069 

141 

2 

414-421 

10.1016/j.sna.2007.10.070 

WOS:000253734900026 

http://linkinghub.elsevier.com/retrieve/pii/S0924424707007479
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This paper describes a novel multipass gas absorption cell based on a spherical absorption cavity. An integrating sphere has been modified to allow the input and output of gas. Measurements have been performed using two hazardous gases: nitrogen dioxide and sulphur dioxide. Nitrogen dioxide is detected in the ultraviolet/visible region at 403 nm and sulphur dioxide in the ultraviolet region at 286 nm. The absorption spectrum of both gases is detected using a broadband deuterium halogen light source as an emitter and a spectrometer as a detector. Nitrogen dioxide concentration is measured using an ultraviolet LED as the emitter and photodiode as a detector. It is reported in this work that trace amounts of nitrogen dioxide (< 5 parts per million, ppm) and sulphur dioxide (< 15 ppm) can be detected using this sensor. A method of calculating the effective optical path length of the sensor is also presented. (c) 2007 Elsevier B.V. All rights reserved. 

integrating sphere; absorption; spectroscopy; nitrogen dioxide; sulphur dioxide; ultraviolet