Detection of toxic gases by a tin oxide multisensor

Abstract

A tin oxide multisensor with eight sensor elements has been utilized to detect different gases that are emitted from the chemical industry. The different sensors have been prepared using the RF reactive sputtering technique. Some components of this multisensor were doped with Pt and Cr by sputtering.Each sensor has been characterized by electrical measurements for detection of atmospheric pollution (nitrogen dioxide, carbon monoxide, toluene, and propanal). The detected gases are toxic and their extreme concentrations recommended in air oscillate from 1 ppm to hundreds of ppm. Detections were carried out with a single gas or a gas mixture (two gases) in dry air at 250 C.The sensitivity and selectivity to these gases were studied. Backpropagation neural networks and their classification results were discussed.

High-Performance Ammonia Sensor at Room Temperature Based on a Love-Wave Device with Fe2O3@WO3−x Nanoneedles

“…Chemical-resistive sensors with metal oxides as a sensitive layer have been commonly used for the detection of toxic agents due to their high sensitivity and stability [1]. Tungsten oxide has been extensively studied as sensitive layer for gases due to its high capacity to detect different analytes, such as NO2 [2].…”

Uncalibrated integrable wide-range single-supply portable interface for resistance and parasitic capacitance determination

“…ating on a very wide range often needs the setting of scaling factors [5][6][7]. In this sense, the limitations of traditional ADCbased front-end can be overcome through a resistance-to-time (or frequency) conversion (RTC) [8][9][10][11].…”

Advanced sensors for real-time control of advanced natural-gas reciprocating engine combustion.

“…Commonly used semiconductor materials are oxides of metals such as zirconium (ZrO 2 ), [1] tungsten (WO 3 ), [2] and tin (SnO 2 ) [3]. These sensors have been applied primarily to the detection of oxygen, and their principles of operation rely on measuring either resistance change (SnO 2 ), conductance (WO 3 ), or current/voltage change (ZrO 2 ) across the semiconductor.…”

“…Applications of these sensors to NO x measurement have been examined. Both WO 3 and SnO 2 sensors show good sensitivity to NO x at relatively low temperatures (200-300°C) when compared with ZrO 2 sensors that operate at a temperature above 500°C. In general, typical problems of metal oxide sensors are poor sensitivity, nonlinear response, long-term drift, and slow response/recovery time.…”

“…To improve sensitivity and selectivity, dopants are often introduced [4,5]. Array sensor design [3,6] has also been investigated for reducing cross sensitivity problems.…”