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Non-dispersive infrared multi-gas measurements in challenging environments

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Heikkilä, Antti
dc.contributor.author Taskinen, Jussi
dc.date.accessioned 2019-05-12T15:00:39Z
dc.date.available 2019-05-12T15:00:39Z
dc.date.issued 2019-05-06
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/37850
dc.description.abstract This research examined the performance of a prototype optical gas measurement device utilizing non-dispersive infrared (NDIR) measurement principle. It was compared to several of its competitor devices. Parameters such as response time, accuracy, cross-sensitivity and spectral width of infrared bandpass filters were measured. The prototype has tunable optical filters that are electrostatically controlled Fabry-Perot interferometers (FPI). They are primarily designed for DC drive that restricts the maximum physical and spectral tuning distance. It was examined how much spectral range increase can be gained by driving certain FPIs with AC signal instead of DC signal. Finally, three wide band thin film infrared bandpass filters were designed, simulated and optimized. They are intended to cover the longer spectral range that a possible future AC driven FPI might use. Compared to its competitors, the prototype device was found to have a good measurement accuracy in gas mixtures. It was also found to have the lowest cross-sensitivity between two main application gases compared to the other devices. The response time of prototype device was slower compared to some of the competitors. It was found possible to control the FPIs designed for DC operation with AC driving signal. The best attained spectral range increase was some 18% but required excessively large control voltages. The performance increase was relatively good but AC drive with high voltages is impractical to incorporate into current products. It was deemed that the parasitic capacitance of the current FPI microstructure is too large to effectively utilize the range extension benefit of AC drive. Three theoretical bandpass filters were designed from different material combinations. After optimization, the first and the third filters were able to meet the requirements while the second could mostly meet them. en
dc.format.extent 111+7
dc.language.iso en en
dc.title Non-dispersive infrared multi-gas measurements in challenging environments en
dc.type G2 Pro gradu, diplomityö fi
dc.contributor.school Sähkötekniikan korkeakoulu fi
dc.subject.keyword infrared technology en
dc.subject.keyword optical gas measurement en
dc.subject.keyword Fabry-Perot interferometer en
dc.subject.keyword ATEX en
dc.subject.keyword optical filter design en
dc.identifier.urn URN:NBN:fi:aalto-201905122952
dc.programme.major Advanced Materials and Photonics fi
dc.programme.mcode ELEC3035 fi
dc.type.ontasot Master's thesis en
dc.type.ontasot Diplomityö fi
dc.contributor.supervisor Sun, Zhipei
dc.programme NanoRad - Master’s Programme in Nano and Radio Sciences (TS2013) fi
dc.location P1 fi
local.aalto.electroniconly yes
local.aalto.openaccess no

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