Nichrome is used for the manufacture of all kinds of heating elements, as it has a high resistivity, due to the fact that it is an alloy and consists of several specially selected metals (80% Ni, 19.5% Cr, 1.45% Si). It is their nichrome that makes the EPSN soldering iron heating element; if it fails, you can independently restore the soldering iron by wrapping a new wire. Also now become very popular electronic cigarettes in which again their high resistance wire coil is used, used as an vaporizer.
Naturally, nichrome alloys are somewhat different from each other, but all of them have a very small temperature coefficient of electrical resistance, which means that with a change in the temperature of the resistance of nichrome changes slightly. You can also make a thermocouple yourself from nichrome and other manganin metal, for this it is enough to twist these two wires together and connect to a powerful (100-300W) transformer or power supply, and close the circuit with a carbon electrode at the other end. Get a ball, which will directly give us information about the temperature.
On sale there are a variety of diameters of nichrome wire, which allows you to create almost any power heating device. Usually they are wound on plastic baboons 100 feet (30.48 meters) long. Resistance is easily calculated because the seller indicates the resistance of a wire one foot long (0.3048m). When creating heating coils, keep in mind that with increasing temperature, the resistance of metals increases.
Cost: ~ 247