Editing Heating element (section)

=== Tubes (Calrods®) ===
[[File:Tubular Electric Heater diagram.svg|thumb|Tubular electric heater. {{ordered list|Resistance heating element|Electrical insulator|Metal casing}}]]
[[File:Calrod-1A.jpg|alt=Tubular Heating Element|thumb|Tubular oven heating element]]Tubular or sheathed elements (also referred to by their brand name, Calrods®<ref>{{Cite web |title=Electric Stoves, Calrods and Cooking with Electricity |url=https://edisontechcenter.org/Cooking.html |access-date=2024-11-15 |website=Edison Tech Center |language=en}}</ref>) normally comprise a fine coil of resistance wire surrounded by an electrical insulator and a metallic tube-shaped sheath or casing. Insulation is typically a [[magnesium oxide]] powder and the sheath is normally constructed of a copper or steel alloy. To keep moisture out of the [[hygroscopic]] insulator, the ends are equipped with beads of insulating material such as ceramic or silicone rubber, or a combination of both. The tube is [[Wire drawing|drawn through a die]] to compress the powder and maximize heat transmission. These can be a straight rod (as in [[toaster oven]]s) or bent to a shape to span an area to be heated (such as in [[electric stove]]s, [[oven]]s, and [[coffee maker]]s).