2025 SMSI Bannerklein

P14 - Improving sensor performance of gas sensors by micropumps

Event
22. GMA/ITG-Fachtagung Sensoren und Messsysteme 2024
2024-06-11 - 2024-06-12
Nürnberg
Band
Poster
Chapter
Poster
Author(s)
O. Zett, M. Henfling, A. Bußmann - Fraunhofer EMFT,München
Pages
480 - 485
DOI
10.5162/sensoren2024/P14
ISBN
978-3-910600-01-0
Price
free

Abstract

The detection of different gases is required in many technical applications or safety relevant devices. The detection threshold, accuracy and response time are often limited and insufficient for demanding applications. To increase sensor performance, increased pressure can be beneficial. In this publication we demonstrate the combination of a commercially available CO2 sensor that uses the photoacoustic NDIR sensing principle and a micro diaphragm pump fabricated by Fraunhofer EMFT. Several possible advantages result from this combination: improved response times, wider detection limits concerning the upper and lower limit, actual volumetric measurements and sharper temporal resolution. We use a custom made measurement setup and a reference system to validate these claims. Our results show a shift of the sensor signal by over 40% when increasing the pressure in the measurement chamber by 200 mbar with a micropump. We also observed a signal reduction of over 30% when reducing the pressure by 200 mbar with a micropump. These intentional signal shifts can also be achieved with sensors working with different sensing principles due to the physics of the ideal gas law. Furthermore, we show an improved response time. In future the different configurations that we tested in this study will be combined into one configuration. In addition, smaller micropumps from Fraunhofer EMFT can reduce the overall system size significantly. The resulting measurement unit can address challenging applications in gas sensing, due to the improved sensor performance.

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