| 摘要 |
PROBLEM TO BE SOLVED: To correct a cold junction compensation error due to a terminal temperature distribution in a simple modification of software by adding a preliminarily set correction value for each input channel to a reference temperature of each input channel. SOLUTION: A reference temperature Tc is obtained by a cold junction compensation thermometer RJC set to a central part of a terminal 10. A cold junction temperature of each thermocouple Tc1-Tc6 is actually measured and a deviation temperature e1-e6 to the reference temperature Tc is obtained. The deviation temperature is added to the reference temperature Tc, so that a cold junction correction temperature t1-t6 for each thermocouple Tc1-Tc6 is obtained. A thermoelectromotive force Vc1-Vc6 corresponding to each cold junction correction temperature t1-t6 is obtained from a thermoelectromotive force table stored in a memory and added to a thermoelectromotive force of each measured thermocouple Tc1-Tc6, whereby a cold junction correction thermoelectromotive force V1-V6 is obtained. Finally, the cold junction correction thermoelectromotive force V1-V6 is converted to a temperature Th1-Th6 according to the thermoelectromotive force table and displayed to a display device 21.
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