Using phone app to monitor string tension (Part-2/2)

Based upon testing using CARLTUNE (IPhone and android), the app will display a frequency of approximately (+/-10Hz) 1144Hz if you hit the sweet-spot on your racquet against the base of your palm, for tension of 22lbs. Basically is the average after several such hits.

Approximate CarlTune reading for 22lbs tension

Verifying tension on the newly strung Yonex Aerosonic

Please perform the action as close as possible to the phone mic for best results. I did discovered the phone can be further away if you are in a enclosed and closed room. In this scenario I try to keep a shuttle in the air gently via tapping, with the app monitoring the Hz of the hits.

Tested the procedure with racquets strung with Yonex Aerosonic (0.61mm), Yonex BG66 Ultimax (0.65mm), Gosen Pro66 (0.66mm) and Ashaway Zymax62 (0.62mm) which seem to provide similar results.

In addition, I had reverified the tension using the Tension-O-Meter since I just restrung one of my racquets with Yonex Aerosonic @ 22lbs - app shows 1144.xx Hz. Sometimes the result would be within a few Hz of the above. Irregardless, the percentage of error would be small and hence negligible for the purpose of (free) monitor facility.

Thus we can use the following simple formula to determine tension via the frequency readout on the app.

1144 Hz = 22lbs

1 Hz       = 22 / 1144

               = 0.01924

Thus a x Hz  readout would mean tension of approximately = 0.01924 * frequency shown on app (tension in lbs)

True this methodology is not 100% accurate as it is meant to provide a means for monitoring, not provide absolutely accurate readings. There are such commercial app and/or tools but they won't be free!