CONTINUOUS DETERMINATION AND DISCRIMINATION OF MIXED ODOR VAPORS BY ANEW CHEMILUMINESCENCE-BASED SENSOR SYSTEM

A gas sensor that utilizes chemiluminescence (CL) during the catalytic oxidation of odour vapours on a sintered aluminium oxide (gamma-Al2O3 ) layer is proposed. A new technique is applied to determine continuou sly the concentration of each constituent in a mixed vapour by a singl e CL-based sensor. The sensor is heated and cooled periodically in a t emperature cycle between 200 and 740 degrees C at constant heating and cooling rates of +/-9 degrees C s(-1). By measuring the total CL inte nsities in the heating and cooling courses, we can obtain the concentr ation of each constituent for a mixed vapour of ethanol and acetone in air. The lowest detection limit of the concentration of these vapours is of the order of 1 ppm.