Understanding how and when to use internationally
accepted symbols such as the lightning bolt is
an important part of product design.
Graphical symbols have become an integral part
of the world in which we live. Some of the first
written languages were essentially made up of
symbols that conveyed a word, a group of words,
or an entire concept. It is interesting to note
that in some parts of the world languages evolved
as alphabets comprising individual characters
whereas in other areas, such as the Far East,
concepts evolved into more self-contained, abstract
characters. As the marketplace for goods and services
has become more fluid, however, multiple languages
in a global market means that we now need to develop
a common symbolic language to convey critical
information across language barriers.
To address this need, the standardization of
symbols by the International Organization for
Standardization (ISO) and the International Electrotechnical
Commission (IEC) is now in full swing. The two
technical committees responsible for most of this
standards activity are ISO/TC 145 and IEC SC 3C.
The committees have identified four types of symbols:
technical documentation symbols (architectural,
electrical diagram), public information symbols
(rest room, luggage), safety symbols (electrical
hazard, radiation), and function and control symbols
(windshield wipers, earth ground).
This column is designed to help manufacturers
understand the process and progress of symbol
standardization. Information on specific standardized
symbols is provided to illustrate how and when
to use them and ensure that they conform to appropriate
standards. Each column will highlight at least
one safety or function and control symbol. The
definition for each symbol will be given as well
as examples of its proper use.
Figure 1. IEC Symbol 5036.
Figures 2. ISO 3864, electrical hazard.
The lightning bolt shown in Figure 1 is symbol
No. 5036 in IEC 60417, "Graphical Symbols for
Use on Equipment." Although many shapes have been
used for a lightning bolt over the years, this
is the official illustration accepted by IEC.
Note that this bolt has no divots out of the top,
a relatively solid arrowhead, a thin inner middle
line, and the precise angles shown. Any lightning
bolt used other than this one does not conform
to the standard. IEC defines this symbol as: "Dangerous
voltageTo indicate hazards arising from
dangerous voltages. Note In case of application
in a warning sign, the rules according to ISO
3864 shall be adhered to." Figure 2 illustrates
how this symbol is used when it is part of a graphic-only
safety sign or label as defined by ISO 3864, "Safety
Colors, Safety Signs." In Figure 3, the lightning
bolt is integrated into a safety sign or label
in compliance with U.S. ANSI Z535.4.
|Figure3. An electrical hazard
safety label in compliance with ANSI Z535.4.
The next installment of this column will focus
on function and control symbols, and several ground
symbols will be described and illustrated.
Geoffrey Peckham is president of Hazard Communication
Systems (Milford, PA), a company specializing
in the design and production of product safety
labels. For more information, visit http://www.safetylabel.com.
Peckham is chairman of the U.S. technical advisory
group to ISO/TC 145 on graphical symbols. He can
be reached at email@example.com.
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