J type temperature controller.

Dear friends ,

I need to make a j type temperature controller .
PLease suggest me how to proceed , never used one before .

1. I need circuit used for j type thermocouple signal amplification using opamp op07 and diode for cold junction compensation , I have seen temperature controllers using thermocouples in mkt and they use a diode in the back .PLease suggest me design using this diode for cold junction compensation .Please let me know what exactly this cold junction compensation is ? in easy language and what is the purpose of the diode in this design .What is isothermal block? and how does this isothermal block and diode for compensationj are used physically ....

2. I am using pic controller.

3.Please give me some details regarding software also . Do we implement any lookup table for thermocouples or the output from amplifier is linear enough to display on the Display(Four 7 segment display).


Also it should have provision for the k type thermocouple in future.
Any practical experience and self made design experience is welcome thx......



Thanks and regards.