ABSOLUTE RATED: The efficiency of a filter expressed by the percentage of the efficiency of retaining a particle of a certain size on a single pass through a filter with a fractional efficiency above 99 percent.

ABSORPTION: Penetration of one substance into the inner structure of filter media in which a liquid or gas substance is attracted and held within the structure of the absorbing media.

ADSORPTION: Retention of gas, liquid or solids on a surface due to positive interaction between the surface and the molecules of the adsorbed material.

BACKWASH: Reversal of a fluid flow through filtration media to clean or regenerate a filter.

CLARIFICATION: To clear a liquid by filtration or by the addition of agents to precipitate solids.

DEPTH FILTRATION: Method that uses a porous filtration medium to retain particles throughout the medium, rather than just on the surface of the medium. 

ENTRAINED PARTICLES: Particles that are incorporated into a flow and swept along in its flow.

FLOW RATE: The speed at which a liquid flows and is measured in gallons or liters per minute.

HYDROPHOBIC: A water-fearing membrane filter which cannot be wetted by and repels aqueous and other high-surface tension fluids.

MEMBRANE FILTER: Membrane filters will contain particulate larger than the pore size on the surface of the membrane. Particulate smaller than the rated pore size passes through the membrane or is retained within the membrane.

MICRON RATING: The smallest size of particles a filter can remove is measured in microns, a standard unit of measurement in the filtration industry. One micron equals forty millionths of an inch (0.00004).

NOMINAL RATED: The efficiency of a filter expressed by the percentage of the efficiency of retaining a particle of a certain size or larger on one single pass through a filter.

PARTICLE: A unit of material structure; a discernible mass having an observable length, width, thickness, size and density.

POLYPROPYLENE: A thermoplastic polymeric material that is resistant to a wide range of chemical substances.

RETENTION RATING: The measurement of a filter medium to retain particles of a given size.

SURFACE FILTRATION: In surface filtration, particles larger than the pores of the medium deposit on the filter’s surface. Particles that are smaller than the pore size pass through the medium.

THROUGHPUT: The amount of solution that can flow through a filter before clogging occurs.

ZETA POTENTIAL: The potential difference that exists between the surface of a solid particle immersed in a conducting liquid and the bulk of the liquid.

The terms for this word search were submitted by Eaton’s Filtration Division, a manufacturer of industrial filtration solutions.