This paper is concerned with the relations between the vibration level of chain saw and the physiological response on the handler.
Accelero meter, dynamic strain amplifier and electro magnetic oscillograph were used for the measurments of the vibratile action of three directions. The blood pressure and the pulse rate of human subjects(one hundred or so) were measured by means of Riva-Rocci mercury meter, sphygmomanometer and photo electric pulse meter, accarding to the physioiogical bases.
The experiments yielded the following results :
1) On account of the weight of chain saw, our physiological charges increased by hanging it for a few minutes and in table 1 are collected the results of measurements.
2) The human subjects observed by the vibration tests(during 150 secends) are classified into three groups from the values of their stimulative charge.(Fig. 8)
Group A : Max. blood pressure and pulse rate shown the normal increasing values to the vibrate stimulation.(70～90%)
Group B : Either blood pressure or pulse rate shown the decreasing values. (10～30%)
Group C : These values shown the decreasing tendency both blood pressure and pulse rate. (3～5%)
Therefore I consider that the group C will be unsuitable men to the handling of vibrate hand machine as chain saw.