Typically, once you've measured a particular thermocouple millivoltage, you
will go to published standard thermocouple tables to look up the temperature.
The other alternative is to find temperature given millivoltage using polynomial
Typically, once you've measured a particular thermocouple millivoltage, you
will go to published standard thermocouple tables to look up the temperature.
The other alternative is to find temperature given millivoltage using polynomial
approximation formulas.
However, reversing that process can be quite useful. Thermocouple performance
can be simulated by outputting the millivoltage for a specified temperature.
By simulating the thermocouple in that fashion, you don't have to actually immerse
a thermocouple in a controlled thermal environment.
With this simple program (see
the figure), the millivoltage for a given temperature can be found using
an iterative loop and the 8th-order polynomial approximation for a type-K thermocouple.
Several comparisons to table values are made to illustrate the level of accuracy
obtained with this method (see
the table). Alternative thermocouple types and their respective polynomials
can be substituted into this program.
