Study of bowed string motions with optical detectors
Roger J. Hanson, Lawrence L. Dirkes, Andrew J. Schneider · The Journal of the Acoustical Society of America · 1991
Bowed string phenomena have been studied on a system in which both ends of a string are mounted rigidly to a steel beam. Waveforms are studied at the “nut” and the “bridge” ends with photon-coupled interruptor modules (PCIM) [R. J. Hanson, Phys. Teacher 25, 165–166 (1987)]. At positions farther from the ends, where the amplitude of string motion is greater than the linear region of the PCIM, one-dimensional photodiode arrays are used in an arrangement modified from that reported earlier [T. Nakamura, L. L. Dirkes, and R. J. Hanson, J. Acoust. Soc. Am. Suppl. 1 86, S16 (1989)]. Emphasis is on the study of string motions with periods much greater than any natural period of the string which can be obtained with bowing forces greater than the Schelling maximum [R. J. Hanson, A. J. Schneider, and F. W. Halgedahl, J. Acoust. Soc. Am. Suppl. 1 86, S15-S16 (1989)]. The waveforms observed at different positions have been used to investigate the triggering of this motion with a period longer than that of the normal slip-stick bow and string interaction triggered by the Helmholtz “kink.”