The output of a thermocouple is most likely measured in which unit?

The output of a thermocouple is most commonly measured in millivolts. This is because thermocouples operate based on the Seebeck effect, where a small voltage is generated when there is a temperature difference between two junctions made from different metals. The voltage produced is directly proportional to the temperature gradient, and typically, this voltage is at a very low level, usually in the millivolt range.

Using millivolts allows for a more accurate representation of the small changes in temperature that a thermocouple detects. Additionally, thermocouples are often used in environments where quick response times and sensitivity to small temperature changes are essential, which aligns with their output being measured in this unit.

Other units, such as volts or amperes, are not appropriate for representing the output of a thermocouple due to the relatively low voltage levels produced. Watts are used to measure power and are not applicable in this context since a thermocouple does not provide a measure of power but rather a voltage that correlates to a temperature.