What is an acceptable voltage of a thermocouple?

A thermocouple generates a voltage proportional to the temperature difference between its two junctions due to the Seebeck effect. The output voltage of a thermocouple varies depending on the types of metals used and the temperature range, but for many common applications, a voltage of around 30 millivolts is considered typical for a moderate temperature difference.

This voltage level is significant because it is within the operational range for many temperature sensing applications, allowing for accurate readings without interference. At this level, the thermocouple can provide consistent measurements that can be easily interpreted by control systems. While lower voltages like 10 millivolts could be generated in certain situations, they are less common and might not provide reliable readings in practical applications.

Higher voltages, such as 50 millivolts or 100 millivolts, while possible, often indicate either a different thermocouple type or a larger temperature differential that may not apply to standard use scenarios. Thus, 30 millivolts stands out as a commonly accepted output for thermocouples, exemplifying their effective performance in monitoring and controlling heating systems.