Design Considerations for Low Watt Density Blanket and Strip Heaters

The blanket heater gives the engineer a new dimension in appliance design. Low watt density heat permits more efficient design with plastics as well as metals and glasses. An electrical model of the thermal system helps identify parameters within the system. After the specification of thermal constraints, the selection of the blanket heater from an electrical standpoint is facilitated by the ohms per ``square´´ concept. Safety and approval criteria specify a reasonable testing procedure. The conclusion suggests references where the engineer can obtain the necessary technical data to complete most designs.