A coated piezoelectric crystal sensor for acetic acid vapour determination

A novel sensor for acetic acid vapour determination is proposed. This sensor is based on a piezoelectric crystal covered with a film of diethylenetriamine. For the sensor development a system of our own design-consisting of testing chamber, oscillator circuit and measure instruments-has been employed. The sensor shows its activity to the acetic acid vapours for more than 60 days. The selectivity is adequate although some vapours interfere: hydrochloric acid, formic acid, formaldehyde, tributyl phosphate, chloroform, chlorobenzene, acetone and isobutylmethylketone. The sensor described can be applied to detect acetic acid vapours in the presence of other vapours: acetonitrile, acrolein, benzene, n-hexane, ethanol, propanol, n-butyl acetate, isopropyl ether, isoamyl alcohol, ethyl ether, methylene chloride, carbon tetrachloride and toluene. The major advantages of the proposed sensor over other existing techniques are its simplicity, reduced cost and capacity for use in situ.