Abstract
The magnitude of the mechanical impedance was measured, and it was compared with that of physiological response for evaluating the threshold limit value of local vibration of the vibrating agricultural machinery. The results obtained were as follows;
(1) Mechanical impedance-Frequency curves of two human subjectes showed good agreement each other.
(2) The curves exhibited peaks at about 20Hz, 40-50Hz and 120-130Hz. Each peak was related to the resonances of the head-neck systems hand and fingers.
(3) The real parts of mechanical impedance showed a tendency to correspond with vibration sensation and the amount of respiration (O2 consumption).
(4) The authors constructed the power graph, because the real parts of mechanical impedance were almost the same with the power absorbed in body. So it had been suggested that the threshold limit value should be changed by length of working time.
(5) O2 consumption rapidly increased at about threshold limit line obtained from the results of vibration sensation.
