GB/T 8421-2020 Active

This standard specifies a laboratory measurement and evaluation method for the vibration damping of the driver's seat suspension of agricultural wheeled tractors. This standard complies with the requirements of GB/T 18707.1. This standard also specifies evaluation indicators based on test results, clearly defining the input vibration level, involving three levels of rigid rear axles and agricultural rubber-tired tractors without low-frequency vibration damping cab units. Less than 3,600 kg is level 1, from 3,600 kg to 6,500 kg is level 2, and more than 6,500 kg is level 3. Each level includes a group of tractors with similar vibration characteristics.
This method tests the vibration damping effect of the seat suspension on the driver's whole-body vertical vibration within the range of 1 Hz to 20 Hz. This test method is not applicable to vibrations on the driver outside the seat (for example, vibrations of the driver's feet on the floorboard, control pedals, or hands on the steering wheel).
Note: The test criteria of this standard are for driver's seats of agricultural tractors used in conventional design. Tractors with independent front or rear axles, or tractors with independent front and rear axles, and low-frequency cab suspensions will produce very distinct vibration characteristics. These vibration characteristics can be measured according to GB/T 10910, or using other methods to measure and evaluate the performance of the seat suspension on such tractors.