Amelioration of the selectivity properties

Amelioration of the selective detection properties of Sn02 sensors using metallic filters 

Researchers, being able to elaborate a material sensitive to the action of certain gases, instead alter the natnre and/or the composition of the gaseous phase in contact with the sensitive element. 

In fact, such an evolution of the gaseous phase can be performed either mechanically or chemically. 

In the first case, we use a molecular sifter to let through the molecules whose size are fit for the applications and which are shaped like a pulvemlent or sintered material for which the size of the pores is perfectly defined. 

In the second case, we use catalysts capable of rendering certain interfering gases inactive. The oxidation of carbon monoxide in carbon dioxide on a metal is a typical example. These catalytic elements could be directly mixed with the sensitive element or shaped as a porous film and deposited at the surface of the sensitive element. 

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Phy sical Chemistry of Solid-Gas Interfaces 9.6. Amelioration of the selectivity properties... 

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