Gas sensor materials composed of carbon mixture or metal-containing carbon mixture obtained as evaporated matter by arc discharge which occurs by passing an alternating current or a direct current with electric current density of 0.8 to 3.5 A/mm.sup.2 on discharge surfaces of carbon electrodes or metal-containing...http://www.google.fr/patents/US6105417?utm_source=gb-gplus-shareBrevet US6105417 - Gas sensor
