H ELECTRICITY
H05 ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
H05B ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
3/00 Ohmic-resistance heating
H05B3/20 Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
H05B3/26 heating conductor mounted on insulating base
H05B3/262 the insulating base being an insulated metal plate