Abstract: The invention relates to a sensor comprising a piezoelectric crystal with a polyarylene thioether-containing coating, the coating containing at least one polyarylene system having repeating units of the formula I, —[(Ar1)n—X]m—[(Ar2)i—Y]j—[(Ar3)k—Z]l—[(Ar4)o—W]p—  (I) which contain at least one thioether group, in which Ar1, Ar2, Ar3 and Ar4 are identical or different aryl systems having from 6 to 18 carbon atoms, W, X, Y and Z are identical or different linking groups, selected from the group comprising —SO2—, —S—, —SO—, —O—, —CO—, —CO2—, alkylene or alkylidene having from 1 to 6 carbon atoms and —NR1—, where R1 is an alkyl or alkylide group having from 1 to 6 carbon atoms and at least one linking group must be —S—, n, m, i, j, k, l, o, p are, equal or different, integers zero, 1, 2, 3 or 4, their sum havin

Abstract: A sensor for oxidizing agents contains an oxidizable aromatic polymer. The sensor comprises a piezoelectric crystal coated with a porous or non-porous layer that contains the oxidizable aromatic polymer.

Abstract: The crystal oscillator sensor is provided with a coating comprising a polymer having olefinic side groups. The coating polymer used is, for example, substituted polyacrylate, polymethacrylate, polystyrene or polyester. The sensor is suitable for detecting ozone.