The factors that have to be taken into account to get to the correct DT:
Gender, age, Type of hitting (with spin or without), Type of string (string stiffness factor), Arm injuries, Racket head size, string patterns.
All these factors have to be worked out to give you the Dynamic Tension that suits you.
With the addition of the Beers ERT 300 tension tester, the Tension Advisor and my Racquet tune programs I can now work out the different string combinations / Tensions / and racket sizes to give you the same Dynamic Tension (DT) every time.
note:-The Dynamic Tension (DT) is also known as the String Bed Stiffness (SBS)