Patent ID: 7352187

Claim:
A vacuum measuring gauge, comprising: a housing with a wall comprising electrically conductive material and forming an interior wall surface delimiting a reaction region, a field emission cathode for emitting electrons into the reaction region, with an emitter area arranged at the wall surface which is at least intermittently taken up by an emitter surface, an electrically conducting gate intermittently covering the emitter area, being electrically insulated from the emitter surface, and being supported by electrically insulating spacer means intermittently filling a gap between the emitter surface and the gate and spacing the gate from the emitter surface by a substantially constant gate distance in a direction normal to the emitter surface, as well as a feedthrough connected to the gate and leading through the housing to outside of the housing, and an ion collector arranged inside the reaction region at a distance from the field emission cathode, as well as a feedthrough connected to the ion collector and leading through the housing to outside of the housing.