Depth filter

A filter that does not have a defined pore size or structure. Particles are entrapped or adsorbed both within and on the filter due to a random matrix or structure that creates a tortuous path through the filter.

FAQ
Depth filter is a filter that does not have a defined pore size or structure. Particles are entrapped or adsorbed both within and on the filter due to a random matrix or structure that creates a tortuous path through the filter.
A membrane filter usually traps all contaminants bigger than the pore size on the surface of the membrane. Whereas, a depth filter is a filter consisting of either multiple levels or a single level of a medium that has depth. This will capture contaminants on the structure rather than the surface.
Depth filtration is multiple layers of media, or a thicker media that forms a path to retain particles. This type of media usually retains larger particles at surface level and then finer particles through the layers or thickness.
Nominal filter retention (efficiency) is the particle size that is retained at a given percentage of efficiency (often expressed at 98%). This is usually how depth filters are specified.