Temperature measuring device with thermocouple

Claim 1

A temperature measuring device comprising: a thermocouple (M 1 , M 2 ) having a first output signal (V 1 ) and a measuring point (A); reference contacts (C 1 , C 2 ) connected to said thermocouple; a temperature detecting means (3), having a second output signal (V 2 ), arranged in the vicinity of said reference contacts (C 1 , C 2 ), for detecting the temperature variation of said reference contacts (C 1 , C 2 ); a processing means for calculating the temperature at said measuring point (A), said processing means comprising: (i) a differential amplifier circuit (5), having a third output signal (V 3 ), for amplifying said thermocouple output signal (V 1 ); (ii) a linearization circuit, having a fourth output signal (V 4 ), (6) for linearlizing said temperature detecting means output signal (V 2 ); (iii) an amplifier circuit (7), having a fifth output signal (V 5 ), for amplifying said linearized temperature detecting means fourth output signal (V 4 ); and (iv) a buffer amplifier circuit (8) for amplifying a resultant voltage signal (V 3 +V 5 ) obtained by combining said differential amplifier third output signal (V 3 ) and said amplifier circuit fifth output signal (V 5 ) and outputting a sixth output signal (V 6 ) which corresponds to the temperature at said measuring point (A); and transmission lead wires (M 3 , M' 3 ) for connecting said reference contacts (C 1 , C 2 ) with said processing means to transmit said thermocouple output signal (V 1 ), and transmission lead wires (M 6 , M' 6 ) for connecting said temperature detecting means (3) with said processing means to transmit said temperature detecting means output signal (V 2 ).