Tennis Racquet's String Tension Measurement

Works. Simply works. Refreshing to have an app does what is promised. Works very well and seems to be (intuitively) spot on without calibration for my device. Wow...even does hybrid strings. The only thing lacking is the saving of data to review later. Even lacking that (I can write down the measurements), I still think the high cost is worth it. Great app that really works. Hats off to the developers.

— Jim N.

Absolutely amazing! I never knew what was the exact tension of my racquet but not anymore. Now within seconds I can measure the tension and know which is the one that fits best for my game. It also allows me to know when it is time to change the string when the tension is too low. I highly recommend for any tennis player that wants to improve his game!

— Boyko Bonev

I am a pro stringer and I must say that this is the best tension measurement app I have ever seen, it is accurate, easy to use and the calibration mode makes it unique, big thank you to everyone involved in the creation and development!

— Dimitar Tanev



• The user has to learn how to produce the proper ringing sound close (2 to 10 cm) and in front of the phone microphone. Find the microphone which uses single, very small hole either at the top or at the bottom of the phone.

• Remove the dampener - if you have. 
• Tap the racquet string very gently several times every 1 or 2 sec. with a stiff object. The best way is with pen or pencil, or use another racquet, fingernails, etc.
• While ringing, the resonating racquet string must stay 2 to 10 cm from the microphone, in front of it, especially in a noisier environment. It is shown well in the YouTube video provided for TennisTension mobile app for Google play and App store.
• To receive the exact momentous string tension, define all the necessary racquet and string parameters. If you don't know some of them, default average values are taken for the calculations or the last values that the user put it in. Consider the tension loss.
• TennisTension measures the average tension between main and cross strings of the racquet (for example, if a racquet is strung 25/24 kg, the measurement result will be 24.5 kg).
• String tensions of hybrid strings could be measured as well.
• The error of the measurement result is less than 0.2 kg.
• Calibration is provided, though it is not necessary to use it.

How it works.

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