Patent ID: 6114943
Filing Date: 2000-09-05
Classification: H01C

Abstract:
An apparatus, comprising:a substantially inert, electrically-insulating substrate;a first Pd containing thin film metallization deposited upon said substrate and substantially covered by a substantially hydrogen-impermeable layer, thereby forming a reference resistor on said substrate;a second Pd containing thin film metallization deposited upon said substrate and at least a partially accessible to a gas to be tested, thereby forming a hydrogen-sensing resistor on said substrate;a protective structure disposed upon at least a portion of said second Pd containing metallization and at least a portion of said substrate to improve the attachment of said second Pd containing metallization to said substrate while allowing said gas to contact said second Pd containing metallization, wherein said substantially hydrogen impermeable layer and said protective structure compose a substantially dense dielectric material deposited upon said sensor in a single operation through a common maskwork; anda resistance bridge circuit coupled to both said first Pd containing metallization and said second Pd containing metallization, said resistance bridge circuit determining the difference in electrical resistance between said first Pd containing metallization and said second Pd containing metallization, whereby a hydrogen concentration in said gas may be determined.