Nichrome resistance dependence on temperature
During heating, the resistivity of the metal increases due to the activation of Brownian motion of the atoms. Some alloys, which have a higher resistivity, practically do not change it with increasing temperature (manganin, constantan). This is due to the special structure of alloys and the small average free path of electrons.
Change of conductivity
The temperature coefficient of resistance reflects the change in conductivity when a material is heated or cooled. If the temperature coefficient is designated by α and resistivity at 20°C by Ro, then when a material is heated to the temperature t° its resistivity R1 = Ro (1 + (α(t1 - to))
| Material | Temperature coefficient α1/°C |
| Aluminium | 0,004 |
| Tungsten | 0,004 |
| Iron | 0,006 |
| Constantan | 0,00001 |
| Brass | 0,002 |
| Manganine | 0,00004 |
| Copper | 0,004 |
| Nichrome | 0,0002 |
| Fechral | 0,0001 |
| Electrolytes | 0,02 |
Here is an example. The temperature coefficient for ferrules = 0.0001 /1 degree, and for nichrome α = 0.0002 / 1 degree. This means that heating at 100 °C increases the electrical resistance of the ferrules by 1% and that of the nichrome by 2%.
A piece of nichrome wire of 1 m
| Cross-section (mm) | Electrical resistance at t° 20 °C (ohm) | Resistance at 100 °C (ohms) | Electrical resistance at 1000 °C (ohms) |
| 0,3 | 15,71 | 16,05 | 19,1 |
| 0,5 | 5,6 | 5,612 | 5,72 |
| 0,7 | 2,89 | 2,95 | 3,4,7 |
| 0,9 | 1,7 | 1,734 | 2,04 |
| 1,0 | 1,4 | 1,428 | 1,68 |
| 1,5 | 0,62 | 0,632 | 0,742 |
| 2,0 | 0,35 | 0,357 | 0,42 |
| 2,5 | 0,22 | 0,224 | 0,264 |
| 3,0 | 0,16 | 0,163 | 0,192 |
| 4,0 | 0,087 | 0,0887 | 0,104 |
| 5,0 | 0,056 | 0,0673 | 0,079 |
| 6,0 | 0,039 | 0,0398 | 0,0468 |
| 7,0 | 0,029 | 0,0296 | 0,0348 |
| 8,0 | 0,022 | 0,0224 | 0,0264 |
| 9,0 | 0,017 | 0,01734 | 0,0204 |
| 10,0 | 0,014 | 0,01428 | 0,0168 |
The property of conductors to change their resistance depending on the temperature is used in thermocouples for measuring the temperature of metallurgical processes as well as in drying and firing furnaces.
Supplier
Auremo, a recognized expert in the non-ferrous and stainless steel market, offers you affordable nichrome, ferrules, thermocouples:. Large selection in stock. Conformity with GOST and international quality standards. Always in stock nichrome, fecherrals, thermocouples, the price - the best from the supplier. Wholesale customers the price - preferential. Contact us by phone numbers in the section "Contacts", we are always open to offers. We invite you to partner cooperation.
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Supplier "Auremo" offers to buy nichrome, ferrules, thermocouples on favorable terms, the price - due to the technological features of production without including additional costs. The company's website displays the most up-to-date information, there is a product catalog and price lists. Custom-made products with non-standard parameters are available. The order price depends on the volume and additional terms of delivery.
