The error model of static temperature measurement

the model of dynamic response and methods of reducing the error of temperature measurement about thermocouple are studied based on principle of heat transfer.The error of temperature measurement about thermocouple results from net radiant heat transfer between thermocouple and surroundings.The coefficient of heat transfer in the process of convection has great influence on the error of temperature measurement.The error of therm-ocouple with cover of heat insulation is decreased evidently when gas is pumped with very great velocity.The naked thermo-couple and the thermocouple without pump are not used directly to on-line temperature measurement of gas.To the dynamic process

error is also influenced by their time constant τ

0

.When τ is equal to 3τ

0

the process of dynamic response could be considered

to have been finished.The results of study will not only be used to correct reading error of signal of naked thermo-couple

acquire signal of the higher precision temperature and select appropriate dynamic reading time

but also be supplied scientific basis for on-line temperature control.