Chromel alumel

A thermocouple used to measure the temperature of the exhaust gas in either reciprocating or gas turbine engines. It can be used for measuring temperatures up to 1,000°C. Chromel is the positive lead, and it is normally enclosed in a white insulation for color coding. Alumel is the negative lead, and it is normally enclosed in a green insulation. The alumel lead can also be distinguished from the chromel lead because alumel is magnetic