BS 4274(1968) : AMD 9200
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
View Superseded by
SPECIFICATION FOR TEST CHARTS FOR DETERMINING DISTANCE VISUAL ACUITY
15-08-1996
23-11-2012
Specification
1 Scope
2 Definitions
3 Range of letter sizes
4 Indication of letter size
5 Style and selection of letters
6 Spacing of lines
7 Spacing of letters
8 Proportions and line widths of letters
9 Dimensions of Landolt ring characters
10 Dimensions of illiterate E characters
11 Manufacturing tolerances
12 Luminance contrast
13 Lighting requirements
Appendices
A General recommendations on lighting for test charts
B Simple methods of lighting for externally
illuminated charts
Tables
1 Range of letter sizes and numbers of letters per
line
2 Minimum and maximum lengths of each line of letters
3 Summary of recommendations on lighting for test
charts
Figures
1-4 Simple methods of lighting for externally
illuminated charts. Methods 1-4
Provides basic requirements for test charts designed for either internal or external illumination, employing English capital letters to determine the distance visual acuity. Covers definitions, range of letter sizes, style and selection of letters, spacing of lines, proportions and line widths of letters, dimensions of Landolt ring characters, dimensions of illiterate E characters, manufacturing tolerances, luminance contrast and lighting requirements. BS AMD 9200 RENUMBERS THIS STANDARD
| Committee |
HCC/78
|
| DevelopmentNote |
Superseded and renumbered by BS 4274-1(1968) (10/1996)
|
| DocumentType |
Standard
|
| PublisherName |
British Standards Institution
|
| Status |
Superseded
|
| SupersededBy |
| BS 3521-1:1991 | Terms relating to ophthalmic lenses and spectacle frames Glossary of terms relating to ophthalmic lenses |
| EN ISO 8429:1996 | Optics and optical instruments - Ophthalmology - Graduated dial scale (ISO 8429:1986) |
| BS 3521-2:1991+A1:1996 | Terms relating to ophthalmic lenses and spectacle frames Glossary of terms relating to spectacle frames |
| BS EN ISO 8429:1997 | Optics and optical instruments. Ophthalmology. Graduated dial scale |
| ISO 8429:1986 | Optics and optical instruments Ophthalmology Graduated dial scale |
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