Share Email Print
cover

Proceedings Paper

A low-cost chemical sensor for fixed security applications
Author(s): Stephen K. Holland; Gregory C. Lewin; Robert T. Zehr; Jason D. Baker; Gabriel Laufer; Roland H. Krauss
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

A low-cost infrared sensor that uses room temperature pyroelectric detectors integrated with bandpass filters to provide low-resolution spectral scans of the absorption characteristics of hazardous chemicals was developed for fixed security applications. The sensor provides fast (1 s) and continuous monitoring, detection, and identification capabilities. A unique detection and identification algorithm that uses non-linear computation techniques to account for the exponential nature of optical absorption was developed. Chemical detection and identification is achieved by matching the recorded sensor response vector to an updatable signature library that currently includes the signatures of 14 chemicals. The sensor and algorithm were tested by introducing methanol vapor at optical depths between 225 - 270 ppm-m. Using 1 s signal samples obtained during approximately 20 min. test, resulted in no false positive alarms and 3.4% of false negatives. All false negatives were shown to be due to misidentification of methanol as isopropanol, which is spectrally similar to methanol. By grouping isopropanol with methanol the rate of false negatives was reduced to 0%. Results of the same test using a 30 s signal integration time resulted in no false positive and no false negative alarms.

Paper Details

Date Published: 10 May 2006
PDF: 10 pages
Proc. SPIE 6201, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense V, 62010T (10 May 2006); doi: 10.1117/12.665712
Show Author Affiliations
Stephen K. Holland, Univ. of Virginia (United States)
Gregory C. Lewin, Avir, LLC (United States)
Robert T. Zehr, Univ. of Virginia (United States)
Jason D. Baker, Univ. of Virginia (United States)
Gabriel Laufer, Univ. of Virginia (United States)
Roland H. Krauss, Rammatek, LLC (United States)


Published in SPIE Proceedings Vol. 6201:
Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense V
Edward M. Carapezza, Editor(s)

© SPIE. Terms of Use
Back to Top