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  2. 1951 USAF resolution test chart - Wikipedia

    en.wikipedia.org/.../1951_USAF_resolution_test_chart

    A 1951 USAF resolution test chart is a microscopic optical resolution test device originally defined by the U.S. Air Force MIL-STD-150A standard of 1951. The design provides numerous small target shapes exhibiting a stepped assortment of precise spatial frequency specimens.

  3. Speech interference level - Wikipedia

    en.wikipedia.org/wiki/Speech_Interference_Level

    Speech Interference Level (SIL) is an acoustical parameter calculated from sound pressure levels measured in octave bands.It is used to characterize a noise signal in the frequency range where the human ear has its highest sensitivity.

  4. Safety integrity level - Wikipedia

    en.wikipedia.org/wiki/Safety_integrity_level

    These lead to such erroneous statements as the tautology "This system is a SIL N system because the process adopted during its development was the standard process for the development of a SIL N system", or use of the SIL concept out of context such as "This is a SIL 3 heat exchanger" or "This software is SIL 2". According to IEC 61508, the SIL ...

  5. Help:Printing - Wikipedia

    en.wikipedia.org/wiki/Help:Printing

    Readers with accounts can modify their Special:MyPage/skin.css to customize their individual printing experience. Remember that rules using @media print will show— or not show if that is the intent —in print preview but not printable version. Print URLs for references in citation templates

  6. Template:World map indicating continents - Wikipedia

    en.wikipedia.org/wiki/Template:World_map...

    The parameters align (left, center, or, by default, right) and size (default 300px width) may be used to set the template's horizontal position and the image's size per, respectively, the Location and Size entries here. The parameter heading may be used to replace the default "The seven continents of Earth" heading.

  7. Photo print sizes - Wikipedia

    en.wikipedia.org/wiki/Photo_print_sizes

    The alternative Super series, denoted SnR, nR Plus or nR+, has an aspect ratio of 3∶2 (or as close as possible) and thus provides a better fit for standard 135 film (35 mm) at sizes of 8 inches or above. 5R is twice the size of a 2R print, 6R twice the size of a 4R print and S8R twice the size of 6R. 4D/6D is a newer size for most consumer ...

  8. Solid immersion lens - Wikipedia

    en.wikipedia.org/wiki/Solid_immersion_lens

    A solid immersion lens (SIL) has higher magnification and higher numerical aperture than common lenses by filling the object space with a high-refractive-index solid material. SIL was originally developed for enhancing the spatial resolution of optical microscopy. [1] There are two types of SIL:

  9. Eye chart - Wikipedia

    en.wikipedia.org/wiki/Eye_chart

    An eye chart is a chart used to measure visual acuity comprising lines of optotypes in ranges of sizes. Optotypes are the letters or symbols shown on an eye chart. [ 1 ] Eye charts are often used by health care professionals, such as optometrists , physicians and nurses , to screen persons for vision impairment .