Planimetry methods

Two different systems are used to verify floor tolerances.

• Random traffic: Flatness and levelness. Typically, elevation changes are evaluated from data collected at 30 cm spacing on a grid of planimetry lines.

• Defined traffic: Levelness and flatness tolerances are verified by measuring elevation changes between vehicle wheels along a planimetry line that coincides with fixed forklift wheel paths.

  Warehouses designed with very narrow aisles between high racks for efficient forklift movement require so-called “super flat” paths of defined traffic.

  
  

  The four Fmin numbers

For defined traffic floors, there are four different types of Fmin:

• Leveling Longitudinal Fmin: This relates to the longitudinal tilt angle of the forklift. This number depends on the length of the wheelbase and controls the tilt angle, forward and backward.

• Transverse leveling Fmin: This relates to the transverse tilt angle of the forklift. This number depends on the lateral wheel clearance and controls the roll angle.

• Longitudinal flatness Fmin: This number depends on the length of the wheelbase and represents the rate of change of the forklift’s tilt angle, or the “unlevelness” of the aisle.

• Transverse flatness Fmin: This relates to the rate of change of transverse tilt angle. This a number depends on the lateral wheel clearance and controls the rate of change of the side-to-side roll angle of the forklift.