Quantitative measurement of combustion gases in harsh environments using NDIR spectroscopy

• Main Authors: C. Niklas, S. Bauke, F. Müller, K. Golibrzuch, H. Wackerbarth, G. Ctistis
• Format: Article
• Language: English
• Published: Copernicus Publications 2019-03-01
• Series: Journal of Sensors and Sensor Systems
• Online Access: https://www.j-sens-sens-syst.net/8/123/2019/jsss-8-123-2019.pdf

<p>The global climate change calls for more environmentally friendly use of energy and has led to stricter limits and regulations for the emissions of various greenhouse gases. Consequently, there is nowadays an increasing need for the detection of exhaust and natural gases. This need leads to an ever-growing market for gas sensors, which, at the moment, is dominated by chemical sensors. Yet, the increasing demands to also measure under harsh environmental conditions pave the way for non-invasive measurements and thus optical detection techniques. Here, we present the development of two optical detection systems using non-dispersive infrared absorption spectroscopy (NDIR). One system is intended for civilian use, capable of detecting both CO as well as <span class="inline-formula">CO₂</span> in the range of 4–5&thinsp;<span class="inline-formula">µ</span>m. Furthermore, restrictions regarding size and economic viability are put on this sensor so it can compete with existing sensors. For <span class="inline-formula">CO₂</span>, an estimated resolution of 444&thinsp;ppm is achieved, which is competitive with established sensors on the market. For CO an estimated resolution of 1401&thinsp;ppm was achieved, rendering it necessary to improve this sensor to be competitive with other available sensors. The second system is used in an exhaust system and is capable of detecting <span class="inline-formula">CO₂</span> at 3.2&thinsp;<span class="inline-formula">µ</span>m facing cross-sensitivity with <span class="inline-formula">H₂O</span>. A data analysis method is described to separate the <span class="inline-formula">CO₂</span> and <span class="inline-formula">H₂O</span> signals, revealing a time resolution of 33&thinsp;<span class="inline-formula">µ</span>s.</p>