thanks ErnieM, you guys are right that datasheet and manufacturer's resources are best to learn.
what is the way forward to calculate values for A, B and C

I'd start a new thread and post that question in the Math forum.

My poor ancient brain doesn't remember any data reduction techniques to handle that.

They do specify a "B" constant, that may be the simplified formula noted on the wiki page.

 

I can determine the values of A, B and C for you but as I have indicated there is not much point in doing so.