초록 ▼

A quartz capacitive pressure transducer including a sensing plate and a reference plate disposed on one quartz substrate which are opposed across a gap by a common plate on another quartz substrate to form capacitances. The substrates are maintained in their opposing relationship by an annular frit

A quartz capacitive pressure transducer including a sensing plate and a reference plate disposed on one quartz substrate which are opposed across a gap by a common plate on another quartz substrate to form capacitances. The substrates are maintained in their opposing relationship by an annular frit which seals a chamber between the substrates to a reference pressure. The reference plate is disposed in the area occupied by the frit annulus to provide a reference capacitance that has a zero pressure gradient.

대표청구항 ▼

A pressure transducer with an invariable reference capacitor comprising: a first substrate of insulative material and a second substrate of insulative material; wherein at least one substrate is flexible and will deform in response to a pressure change; wherein said substrates are positioned to oppo

A pressure transducer with an invariable reference capacitor comprising: a first substrate of insulative material and a second substrate of insulative material; wherein at least one substrate is flexible and will deform in response to a pressure change; wherein said substrates are positioned to oppose each other across a gap; an annular frit joining said substrates and forming a chamber between them by sealing said gap to a reference pressure, said annular frit comprising an insulative material with a dielectric constant in excess of one; at least one sensing capacitor plate formed of a conductive material disposed on one of the substrates and located entirely within the area defined by said chamber; at least one reference capacitor plate formed of a conductive material disposed on said one substrate and located entirely within the annular area defined by the frit; at least one common plate formed of a conductive material disposed on said other substrate and opposing said sensing plate in the area defined by said chamber to provide a sensing capacitance between said one common plate and said sensing plate; and another common plate formed of a conductive material disposed on said other substrate and opposing said reference plate in the area defined by the frit annulus to provide a reference capacitance between said other common plate and said reference plate.