ERT Technic AG

DT stands for Dynamic Tension, which describes how tight or loose the entire
string bed of a racket feels when the ball makes contact. Unlike the reference
tension you set on a stringing machine (e.g., 24 kg), DT measures the real,
effective stiffness of the strings inside the racket frame once stringing
is complete.

• Measured in kilopond (kp): DT tells you how much force
  (in kp) is required to deflect the string bed by 1 cm when struck.
• Reflects actual playing feel: While machine tension only
  shows how tightly the string was pulled, DT captures what really
  matters—how the racket responds during play.
• Influenced by multiple factors: DT depends on reference
  tension, string type, gauge, string pattern, and head size. Two rackets
  strung at the same machine tension can have very different DT values.
• Practical range: Most players’ DT values fall
  between 28–46, with lower DT giving more power and comfort, and
  higher DT providing more control and precision.

Inshort: DT is the
true performance indicator of your racket’s string bed—objective, measurable,
and directly linked to how the racket feels in your hand.

For professional stringers, precision and consistency are everything. The ERT300
adds measurable value to your work by allowing you to check results immediately
after stringing, ensuring every racket leaves your hands with the exact
performance the player expects.

• Verify your work instantly: Measure the Dynamic Tension
  right after stringing to confirm accuracy before handing the racket back
  to your client.
• Advise with confidence: Use objective data to explain
  string performance and recommend the ideal restringing interval tailored
  to each player’s needs.
• Replicate success every time: Record DT values for your
  clients and reproduce their preferred setup again and again with total
  consistency.
• Professional credibility: Offering precise, measurable
  insights sets your service apart and builds trust with players at every
  level.

With the ERT300, stringers move beyond “gut feeling” and elevate their service to a
science—delivering reliability and performance clients can feel on the court.

One of the biggest challenges for players is recognizing the right moment to restring.
Strings rarely break at the perfect time—they usually lose their performance
long before snapping. The ERT300 solves this by giving you clear, objective
guidance: a drop of just 10–20% in Dynamic Tension (DT) compared to your
original measurement means your strings are no longer performing at their peak.

• Maintain consistent
  performance:
  Playing with fresh tension ensures your shots stay accurate, powerful, and
  predictable.
• Protect your arm and joints: Overly loose strings absorb
  less shock and can increase the risk of elbow and shoulder strain.
• Save money and time: By tracking the actual tension
  loss instead of guessing, you can restring exactly when it’s needed—not
  too early, not too late.
• Build your own schedule: Every player, string, and
  racket is different. The ERT300 helps you establish a personalized
  restringing rhythm that fits your playing frequency and style.

With this data-driven approach, you’ll always know the perfect moment to restring—no guesswork, no surprises.

The ERT300 turns subjective feel into measurable data. Instead of relying only on your wrist or ear, it provides exact readings of your racket’s current Dynamic Tension (DT). This means you always know whether your strings are still performing at their best or if they’ve already started to lose tension.

• Objective measurement: No more guessing how tight or
  loose your strings really are.
• Personalized performance
  profile: Every
  player feels tension differently—data helps you dial in the exact setup
  that matches your style of play.
• Consistency across rackets: Keep all your frames at the
  same tension level, whether for training or match play.

With this precise feedback, you gain full control over your equipment instead of leaving it up to chance or pure experience.