Definition
A nickel-chromium alloy used as one of the two dissimilar metals in a thermocouple, most commonly paired with Alumel to measure high temperatures such as those in turbine engine exhaust gas temperature (EGT) and cylinder head temperature (CHT) systems.
Plain English
Chromel is a special metal made mostly of nickel and chromium. It is used in pairs with another metal to make a sensor that measures very hot temperatures inside an engine.
Context Anchor
Seen in aircraft maintenance when identifying, testing, or repairing thermocouple leads for engine or airframe temperature instruments.
Derivation
The name is a blend of 'chromium' and 'metal' — a trade name coined to describe a chromium-bearing alloy. Knowing this tells you immediately that chromium is the defining ingredient.
Why Pilots Care
Thermocouples using Chromel and Alumel are how pilots and mechanics know what's actually happening temperature-wise inside an engine. If the EGT or CHT gauge is reading, it's because two dissimilar metals like Chromel and Alumel are generating a small voltage proportional to heat.
Intuition Check
Chromel is not chrome plating and not just any shiny metal. In this context, it means a specific nickel-chromium wire used in a temperature-sensing pair.
Example Sentence 1
The EGT probe uses a Chromel-Alumel thermocouple to sense exhaust temperature at the turbine.
Example Sentence 2
Chromel maintains stable performance when exposed to the high heat near an operating engine.