The maintenance management in the state of strings can be done by measuring the state of strings of the tennis racket in this application program, and recording this value. It might be also possible to know the Cho substitution time of strings by seeing the changing trend in the state.


The state of strings measures the characteristic frequency that there is a correlation in the relation between the stress and the swerve (surface stiffness of strings) to the string side. It is possible to measure it easily by bringing the strings side close to the Microphone of iPhone, and beating strings in driver's grip etc.Whether it was possible to measure it correctly by confirming displaying corrugate of the power spectrum by the FFT operation can visually be judged. It can know the change in the side pressure by measuring it to putting for several days at each play. It will be able to know the timing of the Cho substitution if it is decided that time when the surface stiffness of strings what percentage initial was downed for myself substitutes Cho.

The home stringer will be able to be used also for the make evaluation of strings that I put. If it understands the difference of which extent was generated in the finish, strings put on the same condition become indices in the aim of steady strike ringing.

It is thought that you can use it as a handy measuring instrument that changes into the measuring instrument like Babolat RDC for a professional stringer. It will become possible for the management of customer's string to become possible at the tennis court, and to advise on the Cho substitution outside to say nothing of the inside of a store the shop according to appropriate timing.

The state measurement of strings of each racket can be managed. When it has two or more rackets, and two or more customers' rackets are managed, it is possible to use it.