Patent ID: 7741584

Claim:
A heater comprising a graphite body configured from a solid self standing body of graphite into a pattern for an electrical flow path defining at least one zone of an electrical heating circuit, said electrical circuit comprising terminal ends for terminals to be electrically connected to said electrical flow path, said graphite body having at least one heating surface, a coating layer encapsulating said patterned graphite body, said coating layer comprises at least one of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and rare earth metals, or complexes and/or combinations thereof; and surface layer disposed on said heating surface, said surface layer comprising at least one of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and rare earth metals, or complexes and/or combinations thereof, wherein the surface layer links the graphite patterned body into one integral unit.