Is an aircraft electrical system necessary to power a cylinder head temperature gauge?

A cylinder head temperature gauge can indeed function without an aircraft electrical system by using a thermocouple. Thermocouples operate based on the principle of thermoelectricity, where a voltage is generated in response to temperature differences between the junction of two different metals. When installed correctly, a thermocouple can measure temperature and provide a reading for the gauge without needing any external electrical power source.

This allows for a more straightforward and often more reliable method of measuring temperatures in an aircraft engine, particularly in situations where electrical systems may be less reliable or when power consumption needs to be minimized. While some designs of temperature gauges may require electrical power, the use of thermocouples presents a viable alternative that eliminates this dependency.