Apparatus for evaluating the concentration of at least one type of chemical in a gas phase has waveguide of porous inorganic material with variable light absorption properties

摘要

The apparatus, containing a chemical detector (2) with at least one waveguide (21, 22), a system (1) for directing a light flow towards the wave guide, and an analyzer for the light flow leaving the detector, has the waveguide made from at least one inorganic porous material impregnated with at least one organic material with light absorption properties that vary according to the concentration of a predetermined type of chemical present in a gas phase (3). The apparatus, containing a chemical detector (2) with at least one waveguide (21, 22), a system (1) for directing a light flow towards the wave guide, and an analyzer for the light flow leaving the detector, has the waveguide made from at least one inorganic porous material impregnated with at least one organic material with light absorption properties that vary according to the concentration of a predetermined type of chemical present in a gas phase (3). The inorganic material is of silicon, which can be monocrystalline, oriented, boron-doped or oxidized, or it can be a chromophore material containing Congo red, bromocresol green, phenolphthalein or indigo carmine. The light emitter can be a laser or electroluminescent diode, with the light flow directed towards the chemical detector by optical fibres (11), while the analyzer contains at least one photodetector (4).