TT/Tonearm/cartridge interaction theory?

Can some one direct me to how the analog works in terms of interaction between Turntable, tonearm and cartridge? I do some clue that the amount of signal that cartridge retrieves from grooves is miniscule and it is important to keep that contact pressure (weight?) to a right amount. What kind of tolerance on this right amount is tolerable without loosing too much of a signal and is ther any other measure for Quality control other than sound? I might have answered my own questions but a I would like little more insight or someone can point out if I have missed any key parameters..

I am structural engineer by profession and am really curious. Thx

Nil