Non-selective NDIR array for gas detection

A miniaturized non-selective optical gas detection system is proposed in this work. The measurement method combines the advantages of optical systems, i.e. aging and drift effects can be corrected, and the versatility of the non-selective gas sensors arrays that make up an electronic nose. The detection module is composed of two matching arrays, one of thermopile detectors and the other of non-substance-oriented filters. Both arrays are fabricated using CMOS compatible processes and bonded together by means of flip-chip techniques. This detection module is part of a measurement setup that also includes a gas cell closed by IR-transparent lenses and a commercial IR source. First measurements with volatile compounds (acetone, ethanol and isopropanol) are reported. Experimental results show the ability of the system to discriminate these substances as far as their infrared spectra differ. (c) 2007 Elsevier B.V. All rights reserved.