Assessment and Optimization for Novel Gas Materials Through the Evaluation of Mixed Response Surface Models

Abstract

In this paper, an innovative methodology aimed at improving the development of novel gas sensors through a process optimization is carried out by applying mixed response surface (RS) models. High accuracy measurements of new conductometric metal oxide gas sensors, obtained by an efficient control of the working conditions, are gathered. The response of metal–oxide–semiconductor gas sensors changes significantly when the sensors operate at different temperatures and target gas concentrations. To consider all the sources of variability there involved, the RS methodology was applied, including random effects, to improve and optimize the performance of these new gas sensors. More precisely, the optimization is performed exploiting a limited number of observations, systematically collected with an ad hoc measurement system, and it considers external sources of variability, satisfying at the same time stringent requirements. Furthermore, the statistical results and the relative assessment of novel gas materials are obtained by considering fixed as well as random effects, where random variables are considered for\ud better controlling the optimization step

Optimization of Perovskite Gas Sensor Performance: Characterization, Measurement and Experimental Design

“…In the gel combustion method, nitrate hydrates salts of Y and Co powders were mixed with citric acid and dissolved in distilled water. The solution, once heated, becomes first a sol, which then leads to the formation of a dusty grey-colored gel, which is dried at a temperature of about $100{}^{\circ }$C [13] and then brought to $600{}^{\circ }$C for 4 h. The gel bursts into flames after about ten to twenty seconds (see Figure 1) with a sudden increase of temperature, producing a spongy light black-colored powder; subsequently, the temperature is increased up to $900{}^{\circ }$C and maintained for 48–72 h to complete the solid state reaction. The combustion suddenly increases the temperature of the gel and exploits the instant gas expansion to produce a nanoporous grain structure, as will be shown in the images obtained by SEM analysis.…”

A Robust Method for Tuning Photoacoustic Gas Detectors

“…7: one for the predicted resonant frequency, and one frequency either side of resonance. As the acoustic frequency moves closer to resonance, the peak output increases, as predicted by (10). In this case, the optimum setpoint for photoacoustic resonance is v tec = 1.575 V. B. Photodetector-based Harmonic Localization Fig.…”

“…• C [10]), and as a result are not ideal in explosive environments. New sensing structures based on lead sulfide have recently been reported [11] for sensing methane in the 1 %-5 % range, approaching the critical Lower Explosive Limit (LEL).…”

“…Localization of gas leaks was investigated in [17] for the case of propane gas. Recent developments include enhanced metal oxide sensor designs [10] and microcantilever sensors [18]. Optical fibers have also been employed for fiber-based gas sensing [19] and using interferometric techniques [20].…”

Stability evaluation of YCoO3 basedperovskites used for NO2 detection

“…The materials 1, 2, 5 are prepared by the gel combustion technique which, in principle, allows to prepare nanostructured powders and to increase the surface area and the surface reactivity [18]. For this preparation, nitrates and citric acid are mixed with ammonium nitrate at 100°C, and the viscous sol before the gel formation is transferred to the furnace at 600°C for 4 h where the gel burns into flames for the first 20 s. Then the temperature is increased up to 900°C and after an exposition of two days the particles are visibly fine and ready for the application.…”