Prediction of TTS for hand intermittent vibration

Temporary Threshold Shift (TTS) is often used as an indicator of the effect of hand-transmitted vibration on the human body. An experiment for the prediction of TTS in exposure to intermittent vibration was conducted in the present study to examine the exposure equivalent rule, as well as the equations for growth and recovery TTS. It was found that the prediction of TTS obtained here was in good agreement with measured TTS. This estimation procedure for predicting TTS was compared with the notification of the Labor Ministry in Japan, in which control of the operation time and the rest time for hand-vibrating tools was described. The results suggest that the rest time of five minutes for a continuous exposure time of 30 minutes with low-level of vibration tools should be extended to 10 minutes of rest time.