Pyrometer is used for measuring relatively high temperatures, such as are encountered in furnaces. Most pyrometers work by measuring radiation from the body whose temperature is to be measured. Radiation devices have the advantage of not having to touch the material being measured.

Induction hardening is a method of surface-hardening in which the part to be surface-hardened is placed within an inductor coil through which a high frequency current is passed.
Induction hardening is a process used for the surface hardening of steel and other alloy components. The parts to be heat treated are placed inside a water cooled copper coil and then heated above their transformation temperature by applying an alternating current to the coil.

The lower critical temperature is same for all steels Lower critical temperature for steels austenite-to-pearlite transformation is 1333 ºF (723 ºCelsius). Below this temperature, austenite doesnot exist.