OPTICAL TRANSPARENT SENSOR FOR DETECTING SULPHUR DIOXIDE (SO2) IN A GASEOUS SAMPLE

摘要

An optical transparent sensor is proposed for quantifying sulphur dioxide (SO2) in a gaseous sample. The sensor contains an indicator substance which is homogeneously immobilised in the sensor matrix, is brought into contact, at least indirectly, with the sample and the concentration of which changes in the presence of SO2. The change in concentration of the indicator substance can be advantageously followed photometrically as a change in light transmission through the sensor in the UV/VIS regions. The indicator substance is characterised in that it is present as a salt and derived from alkyl-substituted, alkylene-substituted or arylene-substituted ammonium ions of medium chain length, or from polymer anion exchange materials, while the counter-ion is formed from one or more chromium-oxygen compounds selected from the group comprising chromate CrO42- and/or dichromate Cr2O72- and/or polychromates.