Working height standards of aerial working platforms

The most intuitive method to identify the height of aerial working platforms is using meters, for example, 14 m aerial working vehicles, 16 m scissor lift vehicles, 18 m aerial lifts, 20 m self-propelled boom lift, 22 m aerial vehicles and others, it mostly means the working height of the aerial lifts, but is it the same as the actual height of the device, here is some common knowledge of lifts with different heights:

The actual height of 14 m aerial vehicles is 12.3 meters, the actual height of 16 meters Aerial is the actual height of 14.3 m, 18 m aerial vehicles is 16.3 meters, the actual height of 20 m aerial vehicles is 18.3 m, 22 m aerial actual height is 20.3 meters, the parameters above usually mean the aerial platform lift height (ie, the actual height of the bottom of the work platform to the ground).

Why is there such a difference? Because in the design of aerial scissor lift, the human height is included in the calculation, so once the average height of man is added, the scissor lift could achieve high-altitude operations and its safety level is higher.