BS 3693:1992

Committees responsible
Foreword
Recommendations
1 Scope
2 Definitions
3 Factors influencing scale design
4 Determination of scale length and reading distance
5 Basic scales
6 Method of design of scales
7 Index
8 Proportions of scale marks
9 Parallax
10 Other considerations
11 Form of digits
Tables
1 Examples of scale lengths for reading at distances
    300 mm and 1000 mm
2 Direction of movement of the index for increasing
    magnitude of the measurand
3 Dimensions of scale marks expressed as a ratio of
    scale length
4 Examples of character heights for reading at
    distances of 300 mm, 600 mm and 1000 mm
Figures
1 Nomenclature for dials and scales
2 Relations between reading distance and scale length
    with respect to resolution factor
3 Examples of recommended scale marks
4 Recommended shapes of pointer tip
5 Illustrations of types of scales
6 Effect of parallax
7 Measuring range 8 A to 50 A, the subdivisions being
    omitted outside the measuring range
8 Measuring range 80 V to 110 V, the measuring range
    between the dots
9 Measuring ranges 0.06 MOhm to 0.4 MOhm and 0.1 MOhm
    to 2 MOhm, the scale mark bases of the measuring
    ranges being thickened

Design for instruments in which an index moves in relation to a fixed array of scale marks or in which a scale moves in relation to a fixed index.

This British Standard gives recommendations for the design of scales and indexes of analogue indicating instruments in which an index moves in relation to a fixed array of scale marks to display the value of a measured quantity, or in which the scale moves in relation to a fixed index. Basic designs are given for scales for single, dual and multi-range fixed or portable instruments.

This British Standard is applicable to scales with:

1. black or dark coloured scale marks on a white or light coloured background;
2. white or light coloured scale marks on black or dark dials;
3. transilluminated scales.

BS 3693 can be applied in the design of both linear and non-linear scales.

No recommendations are given for the design of scales displayed on cathode ray tubes.

This British Standard can apply to non-electrical instruments.

NOTE The title of the publication referred to in this standard is given on the inside back cover.