DIN 461

Area	science and technology
title	Graphical representation in coordinate systems
Brief description:	Axis labeling
Latest edition	3.1973
ISO	-

The DIN standard DIN 461 contains specifications for the uniform, unambiguous and clear graphical representation of a functional relationship between continuously variable quantities in a coordinate system . The first issue was published in January 1923 under the title "Graphical Representations through Schaulinien".

Examples of axis labeling with qualitative representation

Coordinate axes

For the representation, coordinate axes indicate the framework in which a functional relationship between two variables in a preferably planar, right-angled coordinate system is to be illustrated qualitatively or also quantitatively. A third variable can be taken into account by parallel projection or as a parameter in a family of curves or in a family of characteristics .

Serve for quick orientation

the labeling of the axes with the sizes shown , possibly also with numerical values and units ,
the labeling of the intersection of the two coordinate axes, which is often, but not necessarily, the origin of the coordinate system at which both coordinates assume the value zero.

labeling

Qualitative presentation

Linearly divided axes, but not for the variables and , but for and

{\ displaystyle n}

{\ displaystyle T}

{\ displaystyle \ lg n}

{\ displaystyle 1 / T}

This representation depends on the characteristic course of the variables that are dependent on one another. The values of the variables shown increase from the point of intersection of the two axes, preferably to the right or up. An arrowhead at the end of the axis shows the direction in which the coordinate grows. The plotted size is indicated by its formula symbol (written in italics) under the horizontal or to the left of the vertical arrowhead. The formula symbol should be legible without rotating the image.

The arrows may also be placed parallel to the axes. Then the formula symbols are at the roots of the arrows. If words or formulas are unavoidable instead of formula symbols, the writing on the vertical axis should be legible from the right.

In the qualitative representation, linear divisions should always be assumed on the curves on both axes. The plotted variable can also be used as a function of another variable, e.g. B. in reciprocal or logarithmic context, written. Scales are missing. Distinctive points may be marked.

Quantitative representation

Examples of axis labeling with quantitative representation

Examples of axis labeling for two dependent quantities above the same independent quantity

In this representation, the legibility of numerical information is also important. Each axis has a numbered graduation ( scale ); the numerical values should be legible without rotating the image. The zero points of the abscissa and ordinate axis are each designated by a zero, even if both zero points coincide. All negative numerical values are to be provided with a minus sign.

It is often appropriate to add the scale graduation to a coordinate network. The lettering is then preferably placed on the left and lower edge.

Belonging to the numerical values (perpendicular to write) unit characters are at the right end of the abscissa axis or the ordinate axis at the upper end, respectively between the last two numbers. If there is not enough space, the penultimate number can be omitted. Under no circumstances may the unit symbol be placed in square brackets ( DIN 1313 section 4.3 ). When specifying angles in degrees, minutes or seconds, the unit symbol appears at every numerical value on the scale (in accordance with DIN 1301 without spaces in between).

The notation as a fraction 'size by unit' is also possible, e.g. B .; then, however, there is no longer a functional connection between quantities, but between numbers. Furthermore, the symbol of the unit with the word "in" can be attached to the formula symbol for the size, e.g. B. . ${\ displaystyle d / \ mathrm {mm} \,}$ ${\ displaystyle d \; \ mathrm {in \; mm} \,}$

With logarithmic division it is recommended to use a notation with powers of ten; For values between the powers of ten, an abbreviated number is sufficient.

The zero point can lie outside the displayed area if the area between the zero point and the start of the display is irrelevant (suppressed zero point, "section enlargement"), or if it is infinitely far away (e.g. with a logarithmically divided axis).

Multiple dependent variables

When representing multiple variables over the same independent variable, multiple line types (dashed lines, dash-dot lines, etc.) or colors should be used, if necessary. The curves are identified by the size shown (e.g. their formula symbol) or reference symbols (e.g. numbers).

For quantitative information, a separate scale is recommended for each size. The arrangement of several scales is based on clarity.