This standard provides an index table for converting thermocouple emf to corresponding measured temperature and vice versa for converting temperature to corresponding thermocouple emf. The polynomials listed in Appendix A are the polynomials that lead to the index table, so there is no error. The indexing table (E=f(t)) is derived from the corresponding indexing function, and the inverse function table (t=f(E)) is derived from the corresponding inverse function.
GB/T 16839.1-1997 history
2018GB/T 16839.1-2018 Thermocouples—Part 1: EMF specifications and tolerances