1.1 This International Standard specifies, in accordance with ISO 10326-1, a laboratory method for measuring and avaluating the effectiveness of the seat suspension in reducing the vertical whole-body vibration transmitted to the operator of eart-moving machines at frecuencies between 1Hz and 20 Hz. It also specifies acceptance criteria for application to seats on differnt machines. 1:2 This International Standard is applicable to operator seats used on earth-moving machines as defined in ISO 6165. 1.3 This International Standard defines the input spectral classes required for the following earth-moving machines. Each class defines a group of machines having similar vibration characteristics: