OPTIMIZATION OF THE OPERATING-CONDITIONS OF THERMOCOUPLES ALLOWING FOR NONLINEARITY OF THE TEMPERATURE DISTRIBUTION

It is shown that the Peltier heat, previously regarded as a purely con tact characteristic, must be included in the equation describing the h eat-flux balance in the volume of a sample (simplified Ioffe-Stil'bans equation). Analytical expressions for the temperature distribution in a loaded thermocouple, which describe the main deviations from the li near distribution, are derived by a self-consistent calculation allowi ng for a temperature dependence of the Peltier heat. Equations which e xtend the Ioffe relations to the case of large temperature differentia ls and large heat fluxes are obtained for the efficiency of a thermoco uple. (C) 1997 American Institute of Physics. [S1063-7826(97)03110-4].