Open AccessIdentification of H2S Impurity in Hydrogen Using Temperature Modulated Metal Oxide Resistive Sensors with a Novel Signal Processing Technique
Author(s) -
Barbara Urasinska-Wojcik,
Julian W. Gardner
Publication year - 2017
Publication title -
ieee sensors letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 10
ISSN - 2475-1472
DOI - 10.1109/lsens.2017.2709345
Subject(s) - components, circuits, devices and systems , robotics and control systems , communication, networking and broadcast technologies , signal processing and analysis
We report here on the results of a study on the response of copper oxide (p-type and mixed) based, low-power microelectromechanical (MEMS) gas sensors to parts per million (ppm) levels of hydrogen sulfide in a hydrogen atmosphere. It is shown that a thermally modulated metal oxide gas sensor can be used for the identification of the H2S impurity in a reducing environment without the need for a reference gas or baseline signal. It was found that by using this material with a method of transient frequency analysis, a resistive gas sensor can operate reliably in a harsh environment, e.g., pure hydrogen and elevated humidity levels. A linear response in gas concentration was obtained from the analysis of transient sensor signal. This novel temperature modulation technique is more effective than an isothermal method where H2 background is introduced, due to the elimination of drift and additive noise in the sensor response that limits the practical utilization of these low-cost sensors.