Definitions for "Depth filter"
A filter medium consisting of randomly distributed particles or fibers resulting in openings with a non-uniform and tortuous path.
a filter medium that retains contaminants primarily within tortuous passages. ( 395)
It employs a medium with a significant amount of thickness providing 'filtering in depth'. The path through the filter is much longer and random, providing greater possibility of both direct interception and dirt retention. Larger particles tend to be trapped in the surface layers and the finer particles trapped by succeeding layers. Generally the overall performance and dirt holding capacity of a depth filter is better than that of a surface filter.