METHOD FOR TESTING AND MANUFACTURING SPIRAL SPRINGS FOR A TIMEPIECE

A method for inspecting a spiral or a spiral blank arranged to form a spiral, the spiral having to exhibit at least one predetermined resonant frequency, the inspecting method including the following steps:a. applying to the spiral or to the spiral blank a time-varying vibrational excitation to cover a predetermined frequency range,b. identifying at least one characteristic of a resonant frequency, such as a resonance peak, of the spiral or of the spiral blank during the vibrational excitation over the predetermined frequency range,c. submitting to a predicting machine the resonant frequency characteristic identified in the step b. to determine a stiffness of the spiral or of the spiral blank and/or determine whether or not a dimensional correction of the spiral or of the spiral blank is necessary to obtain the predetermined resonant frequency.