Chromel is an alloy made of approximately 90 percent nickel and 10 percent chromium that is used to make the positive conductors of ANSI Type E (chromel-constantan) and K (chromel-alumel) thermocouples. It can be used at temperatures up to 1100 °C in oxidizing atmospheres. Chromel is a registered trademark of Concept Alloys, Inc.[1]
Chromel A
Chromel A is an alloy containing approximately 80% of nickel and 20% chromium (by weight). More precisely, Cr 20%, Fe 0.5%, Si 1%, Ni remainder [2] It is used for its excellent resistance to high-temperature corrosion and oxidation. It is also commonly called Nichrome 80-20 and used for electric heating elements.
Chromel C
Chromel C is an alloy containing 60% nickel, 16% chromium, and 24% iron. It is also commonly called Nichrome 60 and is used for heating elements, resistance windings, and hot wire cutters.
Chromel-R
Chromel R has a composition of Cr 20%, Ni 80%.[2]
Chromel-R was also produced as a woven fabric of chromel wires. It was developed by Litton Industries for use by NASA in the Apollo program.[3] Patches of Chromel-R formed an outer layer of the spacesuit where abrasion resistance was needed.[4] These patches can be seen as silver-grey areas over the white Beta cloth of the main suit. The upper areas of the overshoes, the gloves[5] and patches beneath the life support backpack were of Chromel-R. Gold-plated open-weave Chromel-R mesh has also been used as the reflecting surface for compact-folding parabolic antenna on spacecraft.[6]
