(under subclass 540) Subject matter wherein the condition is a predetermined level of radiation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
578, for flame detection using radiant energy.
584+, for detecting heat levels by thermally emitted radiant energy.
SEE OR SEARCH CLASS
219, Electric Heating,
248, for a heating device combined with a sole plate-type pressure application means (e.g., a flatiron, etc.) including a condition-responsive indicator, subclass 445.1 for an exposed planar support surface for material to be heated (e.g., hot plate, etc.) including an indicator, or subclasses 446.1+ for an exposed planar support surface for material to be heated (e.g., hot plate, etc.) including a sensing means.
250, Radiant Energy, 336.1+, for invisible radiant energy responsive electric signalling; and subclasses 200+ for photocell circuitry.
