BS 4274-1:1968
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
View Superseded by
Visual acuity test types Specification for test charts for clinically determining distance visual acuity
Hardcopy , PDF
13-01-2003
English
26-01-1968
Important note : Users cannot be edited or removed once added to your Multi user PDF.
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
Basic requirements for test charts designed for either internal or external illumination, employing English (Roman) capital letters to determine the distance visual acuity. Provision is also made for the single letter C (Landolt or broken ring) and the single letter E (illiterate E) in various orientations.
| Committee |
CH/172
|
| DevelopmentNote |
Supersedes and renumbers BS 4274(1968) (10/1996)
|
| DocumentType |
Standard
|
| Pages |
12
|
| PublisherName |
British Standards Institution
|
| Status |
Superseded
|
| SupersededBy | |
| Supersedes |
Access your standards online with a subscription
Features
-
Simple online access to standards, technical information and regulations.
-
Critical updates of standards and customisable alerts and notifications.
-
Multi-user online standards collection: secure, flexible and cost effective.