filter (redirected from added filter)

filter /fil·ter/ (fil´ter)

1. a device for eliminating or separating certain elements, as (1) particles of certain size from a solution, or (2) rays of certain wavelength from a stream of radiant energy.

2. to cause such separation or elimination.

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membrane filter  a filter made up of a thin film of collodion, cellulose acetate, or other material, available in a wide range of pore sizes.

Millipore filter  trademark for any of a variety of membrane filters.

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fil·ter (fltr)

n.

1. A porous material through which a liquid or gas is passed in order to separate the fluid from suspended particulate matter.

2. A device containing such a substance.

3. Any of various electric, electronic, acoustic, or optical devices used to reject signals, vibrations, or radiations of certain frequencies while passing others.

4. A translucent screen, used in both diagnostic and therapeutic radiology, that permits the passage of rays having desirable levels of energy.

5. A device used in spectrophotometric analysis to isolate a segment of the spectrum.

v.

1. To pass a liquid or gas through a filter.

2. To remove by passing through a filter.

3. To pass through or as if through a filter.

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filter,

n a material placed in the useful beam to absorb preferentially the less energetic (less penetrating) radiations. See also filtration.

filter, added,

n a filter added to the inherent filter.

filter, compensating,

n a filter designed to shield less dense areas so that a more uniform image quality will be produced.

filter, inherent,

n the filtration introduced by the glass wall of the radiographic tube, any oil used for tube immersion, or any permanent tube enclosure in the path of useful beam.

filter, orange,

n the recommended safelight filter for darkroom illumination when processing intraoral film only. Also called filter type ML-2.

filter, red,

n the recommended safelight filter for darkroom illumination when processing either intraoral or extraoral film. Also called filter type GBX-2.

filter, total,

n the sum of inherent and added filters.

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filter

a device for eliminating certain elements, as (1) particles of certain size from a solution, (2) bacteria and fungi from suspensions of virus, or (3) rays of certain wavelength from a stream of radiant energy.

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bacteria-proof filter

see berkefeld's filter, pasteur-chamberland filter, millipore filter.

Wood's filter

a nickel-oxide filter that holds back all but a few violet rays and passes ultraviolet rays of about 365 nm. See also wood's light.

x-ray filter

see grid (1).