Temperature Modulation of a Catalytic Gas Sensor

Abstract

The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additional information about the gas characteristics can be measured and drift effects caused by material shifting or environmental temperature changes can be avoided. In this work a miniaturized catalytic gas sensor which offers a very short response time (<150 ms) was developed. Operation with modulated temperature allows analysis of the signal spectrum with advanced information content, based on the Arrhenius approach. Therefore, a high-precise electronic device was developed, since theory shows that harmonics induced by the electronics must be avoided to generate a comprehensible signal.

Sniffing speeds up chemical detection by controlling air-flows near sensors

“…While beneficial for wide adoption of our techniques, the sensitivity of the sensors required relatively high ethanol concentrations. Additionally, our measurement of current amplitude could be influenced by a number of factors, such as humidity 51 , 52 , pressure 53 , temperature 3 , 4 , and mean flow rate 54 , 55 . Therefore, the order of measurements were reversed on alternating days to ensure the trends were independent of humidity, pressure, and temperature.…”

“…Improving electronic noses involves improving either the sensor or the system that delivers odors to the sensor. Commonly, a sensor is heated in order to broaden the response of the system 3 , 4 . Odor delivery is a challenging problem and several investigators have designed biologically-inspired devices to deliver the odors.…”

Application of Temperature Modulation-SDP on MOS Gas Sensors: Capturing Soil Gaseous Profile for Discrimination of Soil under Different Nutrient Addition

“…Temperature modulation has successfully enhanced the selectivity of (thick/thin) SnO 2 in distinguishing a single or multicomponent by applying certain modulation or analysis for optimum result as reported in [4][5][6], even on catalytic gas sensor [7]. Moreover, it also succeeded on the TGSs [8][9][10][11].…”

Synthesis and Characterization of Ligand‐Linked Pt Nanoparticles: Tunable, Three‐Dimensional, Porous Networks for Catalytic Hydrogen Sensing

“…At present, three different types of hydrogen gas sensors are commercially available, namely palladium gate metal‐oxide‐silicon field‐effect transistors (MOSFET), metal oxide semiconductor (MOS) sensors, and catalytic combustion devices. [ 3 , 5 , 6 , 7 , 8 ] A major disadvantage of MOS‐based sensors and non‐micro‐machined combustion devices is the high‐power consumption due to high working temperatures (about 400 °C). Furthermore, these sensors have an unfavorably long response time of several minutes, and MOS‐based sensors defy continuous operation because they require recovery after hydrogen loading.…”