A mechanical low pass filter (LPF) was applied to between the human hands and a portable vibrating tool of a grinder, that is, the tool was separated from the hand by the isolator (LPF) for the purpose of protection of the hands. Equiv-alent electric circuits were used for analysis of the mechanical system in which the mechanical impedances of the tool, of the isolator and of the human hand were simulated by mass-capacitance correspondence.

The good effectiveness on this type of the vibration isolation was proved in acceleration measurements in three directions of X, Y and Z. The model being commercially available was also developed using knowledge of the results.