How many millivolts does a thermocouple produce?

A thermocouple typically generates a voltage output that is proportional to the temperature difference between its two junctions. The standard output of many thermocouples, particularly those used in heating applications, is around 30 millivolts per degree Celsius when considering the temperature reading at approximately 1000 degrees Fahrenheit. Therefore, if the temperature differential is significant enough, the cumulative output can reach around 30 millivolts under typical operating conditions. This makes the choice of 30 millivolts the best representative value for many common types of thermocouples used in heating systems, aligning with the practical measurement scenarios typically encountered in the field.