Patent ID: 7989741

Claim:
Microwave warming apparatus comprising a housing defining a heating waveguide having a pair of opposite electrically conductive end walls and electrically conductive longitudinal walls extending between the end walls, said walls enclosing a heating cavity; an integral electrically conductive ridge projecting from one of the longitudinal walls and extending along the waveguide between the end walls; a slot having opposite ends and extending from the outside through said one longitudinal wall and said ridge into the heating cavity, said slot being adapted to receive a cartridge containing a tube so that the tube extends through the slot into the heating cavity; means for coupling electromagnetic energy having a selected heating frequency into the heating waveguide to heat the contents of the tube; a first receiving waveguide extending inside said ridge adjacent to the slot so that when the cartridge is received in the slot, the first receiving waveguide can pick up thermal radiation emanating from a first segment of the tube and produce a corresponding waveguide-generated signal, and a radiometer that operates at a selected detection frequency and is responsive to the waveguide-generated signal for producing a corresponding temperature signal.