Influence of the measurement conditions on the sensitivity of SnO2 gas sensors operated thermo-cyclically

Toward portable breath acetone analysis for diabetes detection

“…A similar behavior was previously observed even for back-heated SnO 2 sensor during CO detection. There, the sensor response to 800 ppm CO decreased from about 700 to 400 with decreasing inlet flow rate from 0.2 to 0.05 l/min [41]. In that case, however, the volume of the testing chamber and the carrier gas flow rates supplied were both considerably smaller than here [41].…”

“…There, the sensor response to 800 ppm CO decreased from about 700 to 400 with decreasing inlet flow rate from 0.2 to 0.05 l/min [41]. In that case, however, the volume of the testing chamber and the carrier gas flow rates supplied were both considerably smaller than here [41]. This suggests that if sufficient flow rate are not supplied, diffusion-limited instead of reaction-limited sensor response are measured leading to a poor calibration of the sensor signal.…”

Selectivity of Catalytically Modified Tin Dioxide to CO and NH3 Gas Mixtures

“…These include modulation of temperature regime of sensors operation, such as pulsed-temperature [3] or cycled-temperature regime [4]. Another approach is the modulation of the sensor measurement principle.…”

“…Perhaps, the selectivity of CO and ammonia detection in gas mixtures could benefit from the strong distinction of the temperature dependence of sensitivity in the SnO2/PdOx-CO ( Figure 5) and SnO2/RuOy-NH3 systems ( Figure 6). The issue of sensor surface poisoning at low temperatures could be overcome by an appropriate modulation of the operating temperature, e.g., pulsed heating to desorb impurities or applying a temperature gradient to the sensing layers [4,29]. However, this is a matter for further research with these materials.…”

Studies of NO2 Gas-Sensing Characteristics of a Novel Room-Temperature Surface-Photovoltage Gas Sensor Device

“…In this paper the results of systematic studies of the usable gas-sensing characteristics of our new SPV gas sensor device are presented, including the determination of the influence of gas flow rate of NO 2 at constant relative concentration in synthetic air on the variation of SPV amplitude versus time, as well as the respective gas sensor dynamic parameters, such as response and recovery times. The influence of gas flow rate at constant relative concentration on the gas sensor response characteristics has recently been investigated by several groups, among others by Eklöv et al [20] for the Pd-MOSFET sensors in H 2 detection, by Lezzi et al [21] for the RGTO SnO 2 film-based conductometric sensor for CO detection, by Utriainen et al [22] in the comparative analysis of a miniaturized ion mobility spectrometer and metal oxide gas sensor for the detection of toxic organic vapors, by Kevin et al [23] for SnO 2 film-based conductometric sensor mainly for CO detection, by Gmür et al [24] for the metal-oxide-based gas sensor microarrays mainly for isopropanol detection, and by Righettoni et al [25] for portable WO 3 gas sensors for breath analysis.…”