ISO 789-2:2018规定了确定后置三点悬挂系统提升能力的试验程序: a） 在整个运动范围内，液压升降机可在下部挂接点施加的最大垂直力； b） 液压升降机可施加的最大垂直力，位于连接至三点悬挂机构的机架上挂接点后部610 mm处，贯穿其整个运动范围。 注1:静态试验可对拖拉机进行充分比较。测试结果仅用作比较拖拉机的方法，而不是建议拖拉机可携带的机具尺寸。 注2:本测试程序可用于确定前置三点悬挂系统的提升能力。

ISO 789-2:2018 specifies test procedures for determining the lifting capacity of rear-mounted three-point linkage systems: a) the maximum vertical force which can be exerted by the hydraulic lift at the lower hitch points throughout their full range of movement; b) the maximum vertical force which can be exerted by the hydraulic lift, at a point 610 mm to the rear of the hitch points on a frame attached to the three-point linkage, throughout its full range of movement. NOTE 1 A static test provides an adequate comparison between tractors. The test results are used only as a means of comparing tractors and not as a way of recommending the size of an implement which can be carried by the tractor. NOTE 2 This test procedure can be used to determine the lifting capacity of front-mounted three-point hitch systems.