This part is a kind of semiconductor called AD594.

Function of this product has Monolithic Thermocouple Amplifiers with Cold Junction Compensation.

Manufacturers : Analog Devices

Image and pinout :

Some of the text within the PDF file :

a FEATURES Pretrimmed for Type J (AD594) or Type K (AD595) Thermocouples Can Be Used with Type T Thermocouple Inputs Low Impedance Voltage Output: 10 mV/؇ C Built-In Ice Point Compensation Wide Power Supply Range: +5 V to ؎15 V Low Power: <1 mW typical Thermocouple Failure Alarm Laser Wafer Trimmed to 1؇ C Calibration Accuracy Setpoint Mode Operation Self-Contained Celsius Thermometer Operation High Impedance Differential Input Side-Brazed DIP or Low Cost Cerdip Monolithic Thermocouple Amplifiers with Cold Junction Compensation AD594/AD595 FUNCTIONAL BLOCK DIAGRAM –IN 14 –ALM 13 +ALM 12 V+ 11 COMP 10 VO 9 FB 8 OVERLOAD DETECT AD594/AD595 +A G G +TC ICE POINT COMP. –TC 1 +IN 2 +C 3 +T 4 COM 5 –T 6 –C 7 V– PRODUCT DESCRIPTION The AD594/AD595 is a complete instru [ ... ]

AD594 PDF Datasheet Download