International Standards and Conformity Assessment for all electrical, electronic and related technologies
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Drafting IEC publications



Writing equations & formulae

How to write equations and formulae

As far as possible, make use of the normal text editing options. However, the use of fractions, exponents, integrals and other mathematical elements will require a special equation editor.


Do not use graphics in equations, and never insert an equation or formula as a picture. Equations need to remain editable - once turned into a picture, they can no longer be modified.


Which equation editor to use

We recommend you to work with MS Word's Equation editor 3.0 which is integrated in all Word versions. Besides its mathematical notation possibilities, it allows to configure styles (fonts, sizes etc.) for different purposes.


Important: Word offers an equation editor on the Insert tab.


equation 2010

Do not use this editor - it does not allow to define the style settings required for IEC documents (as defined below).


Working with the MS Word Equation editor 3.0

To create a new equation, select Insert > Object > Microsoft Equation 3.0. This opens up a work area and displays the Equation editor toolbar with a set of palettes.


To edit an existing equation, double-click on it. The Equation editor workspace opens, provided the equation was originally created in the Equation editor.


To quit the Equation editor workspace, click anywhere outside the equation.


Configuring how equation elements are displayed

To comply with the IEC requirements, we recommend you set the parameters in the workspace of the Equation editor as shown below. This configuration will remain valid during subsequent sessions.


1) In the menu bar at the top, select Styles > Define...


equation editor styles



2) In the menu bar at the top, select Size > Define...


Define style image 2



3) In the menu bar at the top, select Format > Spacing


formating spacing image 1


formating spacing image 2


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