Patent ID: 8234906
Filing Date: 2012-08-07
Classification: G01N

Abstract:
1. A method of manufacturing a sensor for gases emitted by combustion, said sensor comprising one or more metal oxides forming a semiconductor directly adsorbing gases without a catalyzed chemical reaction, said semiconductor being of p type or respectively n type and having a sensitive layer having an electrical resistance, wherein (i) the sensitive layer detects nitrogen oxides produced by a bright fire and the electrical resistance of which decreases or respectively increases upon contact with the nitrogen oxides and (ii) the sensitive layer detects one or more partially unburned gases selected from a group consisting of alcohols, aldehydes, ketones, carboxylic acids and amines produced by a smoldering fire and the electrical resistance of which increases or respectively decreases upon contact with the one or more partially unburned gases, wherein the metal oxide is deposited once or several times by one of ink screen printing, sol-gel and sputtering techniques on an alumina or silicon insulating substrate covered with layers of silicon oxides or nitrides, said substrate then being provided with electrodes and a heating element for maintaining the temperature of the layer of oxides at a temperature chosen between 150° C. and 350° C.