Characterising the methane gas and environmental response of the Figaro Taguchi Gas Sensor (TGS) 2611-E00

Abstract. In efforts to improve methane source characterisation, networks of cheap high-frequency in situ sensors are required, with parts-per-million-level mole fraction ([CH4]) precision. Low-cost semiconductor-based metal oxide sensors, such as the Figaro Taguchi Gas Sensor (TGS) 2611-E00, may satisfy this requirement. The resistance these decreases response exposure reducing gases, methane. study, we set out characterise TGS 2611-E00 an effort eventually yield [CH4] when deployed field. We found that different gas sources containing same ambient 2 ppm level yielded responses. For example, synthetically generated air produced a lower sensor than natural due possible interference from supplementary species air, though specific cause phenomenon is not clear. carbon monoxide small and incapable causing effect. reason, laboratory was selected testing standard naturally incorporate background effects into reference resistance. sensitive temperature water vapour ([H2O]). Therefore, using characterised for five (each inside its own field logging enclosure) large environmental chamber, where logger enclosure ranged between 8 38 ∘C [H2O] 0.4 % 1.9 %. dominated variability gas. A linear model fit derived, resulting root mean squared error (RMSE) measured modelled ±0.4 ±1.0 kΩ corresponding fractional uncertainty less ±3 at 25 1 [H2O]. loggers were landfill site 242 d before 96 after testing. Yet (i.e. air) based on could replicate measurements made field, mostly expected be close background, minor enhancements. This disparity have been cooling dynamics, difference composition during chamber compared or response, either spontaneously environmentally driven. Despite difficulties replicating devised excellent characterisation up 1000 by ratio enhancement bespoke power-type resulted RMSE no more ±1 Ω Ω−1 sensors. parameters then inverted original values used derive [CH4], yielding ppm, limited 28 ppm. Our allows other gases included if necessary characterising additional coefficients. shows above results drop 1.4 2.0 tested With future improvements deriving resistance, offers great potential measuring