Sensors for the Ultra-Fast Monitoring of Explosive Gas Concentrations

The target of this paper is answering the question about the minimum response time of metal oxide semiconductor gas sensors. This question is very important at the monitoring of sudden explosive emission of high concentrations of combustible gases in mines, chemical and oil refinery factories, nuclear power stations, etc. The optimization of the thickness of sensing layer, deposition conditions, material, and working temperature enabled the fabrication of the sensor with very short response time ∼ 160 ms (hexane) in a concentration range up to 12 vol. %. The response time of the sensor was compared with the response time of IR optic sensor based on LED (λ = 3.4 micron) using testing gas mixing installation equipped with ultra-fast valves. The results were proven in field experiment with spike emission of petrol aerosol.