Above circuit design is thermocouple amplifier circuit using CA3193 operating amplifier. The CA3193 is an excellent choice for use with thermocouples.? In the circuit, the CA3193 amplifies the generated signal 500 times. The three 22M? resistors will provide full-scale output if the thermocouple opens.

The  CA3193 are ultra-stable, precision instrumentation, operational amplifiers that employ both PMOS and bipolar transistors on a single monolithic chip. The CA3193 amplifier are internally phase compensated and provide a gain bandwidth product of 1.2MHz. They are pin compatible with the industry 741 series and many other IC op-amps, and may be used as replacements for 741 series types in most applications.

Download CA3193 datasheet for your thermocouple amplifier project reference: download link