Alumel


Also found in: Wikipedia.

alumel

[′al·yü·mel]
(metallurgy)
An alloy containing 94% nickel, 2% aluminum, 3% chromium, and 1% silicon; used to form the chromel-alumel thermocouple.

Alumel

 

an alloy used in pyrometry as the negative ther-moelectrode of the Chromel-Alumel thermocouple and also as a compensation conductor.

The chemical composition of Alumel is 1.8–2.5 percent aluminum, 0.85–2.0 percent silicon, and 1.8–2.2 percent manganese; the remainder is nickel and cobalt. The cobalt is present as an impurity of nickel and, to ensure the required value of the thermoelectric force, its content must be within the range of 0.6–1.0 percent. Thermocouples with Alumel are used in measuring temperatures up to 1000°C. On prolonged exposure at above 1000°C, a change in thermoelectric force becomes very noticeable. Alumel alloys have been developed and used which contain 0.06 -0.1 percent zirconium or 0.06 percent zirconium plus 0.005–0.03 percent boron and other metals. Such alloying of Alumel substantially increases its ductility (at temperatures of 600–1100°C) and durable strength (at temperatures of 700 -900°C), as well as improving the stability of its thermoelectric force at temperatures up to 1250 -1300°C.

REFERENCES

Berkovskii, I. Ia., and A. G. Kolokolova. Nikelevye splavy.
Moscow-Leningrad, 1941. Popov, M. M. Termometriia i kalorimetriia, 2nd ed. Moscow, 1954.
Smiriagin, A. P. Promyshlennye tsvetnye metally i splavy, 2nd ed. Moscow, 1956.
“Issledovanie splavov dlia termopar.” Trudy instituta “Giprots-vetmetobrabotki,” 1964, vol. 22; 1967, vol. 25.

A. L. SHPITSBERG

References in periodicals archive ?
Workability is the major selection factor: Type K thermocouples are designed for inert atmospheres and if the applications are associated with the after effects of oxidizing then Type K Chromel and Alumel thermocouples are the best bet.
The thermocouples are chosen for use in temperature measurements; the thermocouple type is K-type (Chromel +, Alumel -).
The thermocouples used are of K type, chromel (+), alumel (-) alumel, and the measurement field are -50 .
As such, we are developing connectors under similar assumptions with more exotic materials, such as chromel, alumel, inconel, tellurium, and composites for thermal coupling through a contact system.
Specific heat of alumel and chromel alloys near this magnetic transitions.
Twenty-five 30 gauge Chromel Alumel thermocouples (Omega Engineering, Stamford, Connecticut, USA) connected to two underground Campbell CR10 data loggers (Campbell Scientific, North Logan, Utah, USA) were placed horizontally under the litter layer at the mineral soil surface in the first 13 transect plots extending in each direction from the base of the L.
A line of hermetic headers, connectors, and feedthroughs uses pins made of Alumel, Chromel or Copper.
Conventional iron-constantan or chromel alumel thermocouples, for example, begin to lose accuracy and reliability.
Inconel sheathing on the thermocouple leads provides a close match to the thermal coefficient of expansion of the chromel and alumel wires, providing for a long thermal life cycle for the product.
Type K thermocouples are formed by welding together a Chromel (nickel with 10% chromium) wire and an Alumel (nickel with 5% aluminum silicon) wire and are suitable for measuring temperature differences from -200[degrees]C to +1,350[degrees]C.
Limited Tenders are invited for Hermetically Sealed Unit Connectors Mating Connectors Chromel Contacts Alumel Contacts Accessories