Optical sensor for detecting chemical species.

摘要

The present invention pertains to an optical sensor for detecting gaseous or liquid chemical species which comprises a sensing element having a thin film and means of measurement by interference enhanced reflection. The sensing element comprises preferably a flat light reflecting substrate and one or more transparent thin organic or inorganic films or high-polymer films that are formed on said substrate. The detection of the gaseous or liquid chemical species is effected by measuring the change in the light reflection characteristic of the sensing element on the basis of the swelling of the thin film or the change in its thickness or refractive index or the changes in both parameters. The invention concerns also an apparatus including such optical sensor for detecting the presence of a toxic, combustible or flammable gas, vapor or solvent, an alarm and/or a means of running on and off switches or pipelines.