DYNAMIC TENSION VALUE

What is Dynamic Tension (DT)?

Dynamic Tension (DT) represents the actual tension or stiffness of the stringbed — the force the strings exert once the racket is strung.

DT is physically defined as the ball force (in kilopond, kp) required to deflect the stringbed by 1 cm for a short moment (simulating a ball impact).
The international unit is kp/cm, equivalent to Newton/mm.

When you set your stringing machine to, for example, 20 kg, this is only the reference tension.
The real tension — the actual stringbed stiffness — is what the ERT 300 measures and expresses as the DT value.

This DT value is influenced by multiple factors, including the stringing machine, the stringer’s technique, the type of string, and the racket itself.
You can refer to the accompanying documentation to see all influencing factors.

Why is DT so important?

Because DT is the only measurable value that reflects the true stiffness of the stringbed — and that’s what ultimately determines how your racket performs.
It provides a reliable reference for stringing consistency, quality control, and playability.

Convert DT to KP / LBS?

Based on the DT (Dynamic Tension), the approximate stringbed tension in kilograms (kg) or pounds (lbs) can be estimated.
The included DT Disk helps with this conversion. By combining the racket head size and the measured DT value, the corresponding tension weight is determined.

This conversion is based on over 1,000 test measurements from different racket and string combinations, ensuring a high level of accuracy. 

However, please note that this conversion can still vary due to many influencing factors.
It is important to understand that the DT value itself is always accurate, while the conversion into KP or LBS is only a very precise approximation. In short: trust your DT – not the KP or LBS.

Here are some of the main factors that can influence the result:

• Racket head size and string pattern (open vs. dense)
  
• String material and gauge (thickness)
  
• Stringing machine type (constant pull vs. lockout)
  
• Pre-stretch percentage
  
• Knot technique and stringing consistency
  
• Ambient temperature and humidity