Non-dispersive infra-red (NDIR) measurement of carbon dioxide at 4.2 μm in a compact and optically efficient sensor

SENSORS AND ACTUATORS B-CHEMICAL

卷:186

Article

Hodgkinson, Jane¹  Smith, Richard²  Ho, Wah On²  Saffell, John R.²  Tatam, Ralph P.¹ 

[1] Cranfield Univ, Sch Engn, Dept Engn Photon, Cranfield MK43 0AL, Beds, England

[2] Alphasense Ltd, Great Notley CM77 7AA, Essex, England

关键词: Non-dispersive infra-red;    NDIR;    Gas detection;    Optical absorption;    Carbon dioxide;   

DOI  :  10.1016/j.snb.2013.06.006

来源: Elsevier

【 摘 要 】

Non-dispersive infra-red (NDIR) gas detection has enjoyed widespread uptake as a result of development of devices in the standard miniature format for gas sensors, consisting of a cylinder with external dimensions of 20 mm diameter x 16.5 mm height. We present a new design for such a sensor, making use of low-cost injection moulding technology. The design pays particular attention to the problem of maintaining a high optical throughput while providing an acceptable optical pathlength for gas detection. A detailed analysis of the design is presented, with the results of optical raytracing, showing a raytrace estimate for 4% of the total emitted radiation reaching each of two separated detector elements and a pathlength of 32 mm. Finally, we show experimental results obtained with as-manufactured devices, with a short-term limit of detection for carbon dioxide (CO2) estimated at 1 ppm or a noise equivalent absorption (NEA) of 3 x 10(-5) AU. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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