A COATED PIEZOELECTRIC CRYSTAL SENSOR FOR ACETIC-ACID VAPOR DETERMINATION

A novel sensor for acetic acid vapour determination is proposed. This sensor is based on a piezoelectric crystal covered with a film of diet hylenetriamine. For the sensor development a system of our own design- consisting of testing chamber, oscillator circuit and measure instrume nts-has been employed. The sensor shows its activity to the acetic aci d 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 isobutylmet hylketone. The sensor described can be applied to detect acetic acid v apours in the presence of other vapours: acetonitrile, acrolein, benze ne, n-hexane, ethanol, propanol, n-butyl acetate, isopropyl ether, iso amyl alcohol, ethyl ether, methylene chloride, carbon tetrachloride an d toluene. The major advantages of the proposed sensor over other exis ting techniques are its simplicity, reduced cost and capacity for use in situ.