In order to meet requirements for calculation speed and precision of operation in temperature measuring process of thermocouple

a fast and high-precision temperature measurement algorithm is designed. Use idea of Equation Root

combine linear polynomial fitting method with look-up table method to determine temperature interval; and introduces Horner algorithm to simplify complicated indexing formulas; finally

use dichotomy to solve accurately. Experiments show that on hardware platform

which uses ATmega 128 as control core with 16MHz clock

the algorithm can achieve precision of ± 0. 005 ℃ in the range of 0

1 000 ℃

and compared with traditional root finding method

computation time is reduced from 320ms to 80 ms.