Control 02 Loop-One output analogic

[dandrade]

For it reduce the cost, I decided apply the architecture of the drawing.
Data:
Machine of pack of products: Bar seal + furnance
Input 2 sensors of temperature.
Output module power 2-100%

I know that is possible carry out the control, which the alternatives? Calculations,etc...

 

[dandrade]

Two temperature control points: (A)9000W and (B)1500W, where an modulate power 2-100% connected straightly (A) and of contactor (B). As it should be implemented the method of control, as "balance" to power supplied and obtain stability?

I think of calculating calories and power required in function of the error temperature and %% of the cycle of work. Alternative good, estable? Any work method calories?