ISO 22029:2003

INTERNATIONAL ISO
STANDARD 22029
First edition
2003-12-15


Standard file format for spectral data
exchange
Format standard de fichier pour échange de données spectrométriques




Reference number
ISO 22029:2003(E)
©
ISO 2003

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ISO 22029:2003(E)
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ISO 22029:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Format description. 1
2.1 General. 1
2.2 Required keywords. 2
2.3 Spectral data. 3
2.4 Optional keywords. 4
2.5 Ending a file. 6
3 Example of a data file in the EMSA spectral format . 7
Bibliography . 9

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ISO 22029:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22029 was prepared by Technical Committee ISO/TC 202, Microbeam analysis.
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ISO 22029:2003(E)
Introduction
The original EMSA/MAS Standard File Format for Spectral Data Exchange was published in October 1991.
Since then, advances in both microbeam analysis techniques and in PC technology have meant that this
original standard is not fully able to meet modern requirements. The members of ISO/TC 202 (the
International Organization for Standardization, Technical Committee for Microbeam Analysis) propose this
updated version. Every effort has been made to only make those changes that improve or update the
applicability of the standard, whilst minimizing incompatibility with the original version. The remit of TC 202
does not include surface analysis techniques, which are addressed by TC 201, and so references to these
techniques have been removed from the original standard where necessary. The original document also
included examples of coding and telecommunications protocols. Since these are now largely outdated, and
not integral to the formatting of the data, these have also been removed.
This International Standard is presented as the text of the original, with modifications shown in italic text. It is
further noted that one of the originating societies (EMSA) has modified its name since the original document
was published. The society is now officially known as the “Microscopy Society of America” or MSA, the term
“Electron” having been dropped to more fully indicate the work and interest of the membership of the society
in all forms of microscopy.
The virtues of a single standard data format have been admirably related by various authors [1], [2], [3], [4]. It
would often be convenient, after visiting another laboratory in order to use a different type of microanalytical
spectrometer, to be able to return to one's own laboratory to analyse the data, or for a laboratory to be able to
send a spectrum to another group at another location for analysis on their computer. A common format would
also enable test spectra to be transported between data acquisition systems, in order to compare different
data-analysis routines, and would give users greater choice of analysis procedure, based on commercial or
public-domain software.
Obviously, an ideal solution would be for the manufacturers to represent data in a standard format, but they
are unlikely to agree on this without some direction from their customers (the microanalysis community).
Therefore it is highly desirable for EMSA and MAS to proceed with adoption of a standard format. Such a
format does not preclude any research group or manufacturer from having their own, possibly proprietary,
format. Spectral data can be stored internally in any format, as long as there is an option to convert it to the
external standard (and vice versa) for the purposes of exchange. We believe that a standard format should
pose the following attributes.
1) It should be capable of representing the data exactly (without altering the scientific content).
2) The format should be simple and easy to use.
3) It must NOT be tied to any particular computer, programming language or operating system. It should
work on a large number of computers of all sizes, although we cannot guarantee that it will work on
all possible computers.
4) The format should be both human- and machine (computer)-readable.
5) It should be compatible with existing electronic communication networks such as (but not necessarily
limited to) BITNET, ARPANET, and with the phone system (using modems). Future networks will
likely retain compatibility with these.
6) The format should support spectra of interest to the EMSA/MAS community (such as XEDS, EELS,
AES, etc.) and should be flexible enough to accommodate future data sets, not yet specified.
7) Each file should contain enough information to uniquely identify the type and origin of the spectral
data and to reconstruct its significance.
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ISO 22029:2003(E)
8) Where possible, the format should be compatible with various commercial data plotting or analysis
programs (i.e. spreadsheets or graphical analysis packages).
9) The proposed format need not be the most efficient storage mechanism. Its primary goals, stated
above, will generally prevent storage efficiency. If anything, this format will err on the side of
simplicity and ease of use.
The format originally employed by the Electron Microscopy and Microanalysis Public Domain Library
(EMMPDL) at Argonne [1] has the virtue of simplicity, but is too rigid for general use. A recent revision [5]
corrected some inadequacies, but a more serious re-examination is in order. The format proposed by a
previous EMSA Task Force [3], [4] addresses many of the problems but is thought by some microscopists to
be too complicated for everyday use. The VMAS format, whose description [6] runs to 60 pages, is also too
complex for our perceived purpose. A format, named JCAMP-DX, used by the infrared spectroscopy
community [2] is specific and detailed but is somewhat off-target for the spectroscopies of interest to our
community.
The format proposed here follows JCAMP-DX in many ways, but is less complicated and has features tailored
to X-ray, energy-loss and Auger spectroscopies. We circulated a preliminary version of this proposal to
several manufacturers of XEDS systems and have received comments and suggestions, many of which have
been incorporated into this document.
The companion problem of a standard format for digital image storage is similar to that of spectral data, but is
sufficiently different to warrant its own standard. Whereas most spectra are sufficiently compact that they can
be stored in a human-readable form, image data are usually so extensive as to require storage of “raw” binary
numbers. There exist formats for image storage that are in widespread use. One of these (probably TIFF)
should be endorsed by EMSA and MAS, allowing the microanalysis community to take advantage of the large
amount of commercial and public-domain software already available.


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INTERNATIONAL STANDARD ISO 22029:2003(E)

Standard file format for spectral data exchange
1 Scope
This International Standard presents a simple format for the exchange of digital spectral data that has been
designated as an EMSA/MAS standard. This format is readable by both humans and computers and is
suitable for transmission through various electronic networks (BITNET, ARPANET), the phone system (with
modems) or on physical computer storage devices (such as floppy disks). The format is not tied to any one
computer, programming language or computer operating system.
The adoption of a standard format would enable different laboratories to freely exchange spectral data, and
would help to standardize data analysis software. If equipment manufacturers were to support a common
format, the microscopy and microanalysis community would avoid duplicated effort in writing data-analysis
software.
2 Format description
2.1 General
The general structure of the data file format can be summarized as a simple sequential ASCII (text) file. It
begins with a series of header lines which serve to define the characteristics of the spectrum. These header
lines are identified by unique keyword fields which occupy the first 15 positions of each line, followed by a data
field. These are described in detail below. After the header lines, a keyword indicates the start of data, the
data then follow on successive lines in a manner which is defined explicitly within the header. Finally, after all
the data are presented, an end of data keyword indicates the data set is complete. This is diagrammatically
illustrated below.
Header lines
*
*
Successive lines beginning with EMSA/MAS defined keywords, some of which are required and some are
optional
*
*
Start of data keyword
*
*
Experimental data
*
*
End of data keyword
In general, each line of the file either contains a keyword and its associated value or spectral data. All header
lines are readily identified as they each begin with “#” in the first character field or column. This symbol
demarks the start of a 13 character keyword field, providing descriptive information about the data followed by
an associated value. EMSA/MAS-defined keywords (whose definition may be changed only by EMSA/MAS)
begin with a single # and occupy the first 13 columns (characters) of each header line. The keyword itself
consists of at most twelve characters, which directly follow the #, shorter keywords may be employed and any
remaining spaces following the defined keyword may be filled with descriptive text such as unit designation for
ease of legibility when the file is printed (see examples in Table 1). If a position in the keyword field is not used,
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ISO 22029:2003(E)
it must be filled with a space character. The keywords are not case-sensitive, so that #Xunits is interpreted the
same as #XUNITS.
The 14th and 15th character positions (columns) in each header line are occupied by keyword/value field
separators, which consist of a colon followed by a space. The value associated with each keyword starts in
column 16 and may be either textual or numeric as defined by the keyword. Each line of the file may contain
no more than 79 characters (for compatibility with the largest number of computers and computer networks,
and for general legibility on standard width CRT screens). Since the keyword and its separator occupy the first
15 positions, this means that all remaining information following the keyword is limited to a maximum of 64
(= 79 − 15) character positions. The end of line indicator is a carriage return,
...