Which formula is used to calculate Pounds per Linear Inch?

The formula for calculating Pounds per Linear Inch (PLI) is derived from the need to understand how the weight of a roller is distributed over the contact area of the drum width. In this context, using the roller weight in pounds (LB) divided by the sum of the drum widths in inches effectively provides a measurement of how much weight is applied along each linear inch of the roller's contact surface.

This calculation plays a critical role in asphalt paving, as it helps determine the pressure exerted by the roller on the surface being compacted. Proper PLI ensures that the asphalt is compacted adequately without causing damage or deformation to the surface. If too much weight is distributed over a small area, it may lead to excessive compaction, whereas insufficient weight might result in poor asphalt density.

In contrast, the other formulas presented could lead to misunderstandings about the relationship between the roller weight and the contact area. The formula involving multiplication or addition does not accurately reflect the necessary calculation for PLI since it diverges from the fundamental principle of distributing weight evenly over a measured width. Thus, dividing roller weight by the sum of drum widths remains the correct approach for achieving an accurate Pounds per Linear Inch measurement.