1.1 This International Standard specifies, in accordance with ISO 10326-1, a laboratory method for measuring and evaluating the effectiveness of the seat suspension in reducing the vertical whole-body vibration transmitted to the operator of earth-moving machines at frequencies between 1 Hz and 20 Hz. It also specifies acceptance criteria for application to seats on different 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: - rigid frame dumpers 4 500 kg operating mass1) - articulated frame dumpers - scrapers without axle or frame suspension2) - wheel-loaders 4 500 kg operating mass1) - graders - wheel-dozers - soil compactors (wheel type) - backhoe-loaders - crawler loaders - crawler-dozers u 50 000 kg operating mass1), 3) - compact dumpers u 4 500 kg operating mass1) - compact loaders u 4 500 kg operating mass1) - skid-steer loaders u 4 500 kg operating mass1)