SIST ISO 14807:2011

INTERNATIONAL ISO
STANDARD 14807
First edition
2001-10-15
Photography — Transmission and
reflection densitometers — Method for
determining performance
Photographie — Densitomètres à transmission et à réflexion — Méthode
pour la détermination de la performance
Reference number
©
ISO 2001
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not
be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this
file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this
area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
ISO copyright office
Case postale 56 � CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
ii © ISO 2001 – All rights reserved

Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Sampling and handling .5
5 Determination of performance .5
5.1 General.5
5.2 Repeatability determination.5
5.3 Stability determination .6
5.3.1 8 h stability determination .6
5.3.2 7 day stability determination .6
5.4 Bias estimate determination.7
6 Reporting (individual instrument performance).8
6.1 General.8
6.2 Repeatability reporting.8
6.3 Stability reporting .9
6.4 Bias estimate reporting.9
7 Reporting (performance specifications) .10
Bibliography.11
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 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 14807 was prepared by Technical Committee ISO/TC 42, Photography.
iv © ISO 2001 – All rights reserved

Introduction
Over the past few years, the subject of densitometer performance specifications has been discussed at length, with
the observation made that the densitometer customer is met with a plethora of claims and specifications, in a
variety of formats, pertaining to densitometer performance. Furthermore, various manufacturers have often used
different terminology for describing what is speculated to be the same characteristic. With this in mind, this
International Standard was developed and it identifies three characteristics of performance: ISO repeatability, ISO
stability and ISO bias estimate. Standardized methods for evaluating these characteristics are presented herein.
Any or all three of these characteristics can be evaluated and used to describe the performance of an individual
densitometer and will be useful in comparisons of the performance of densitometers.
The first two of these characteristics, ISO repeatability and ISO stability, are evaluated in such a way that, by use of
suitable periodic sampling of production, a densitometer manufacturer can report average or typical repeatability
and stability as specifications for a particular class, type or model of densitometer. However, ISO bias estimate
cannot necessarily be meaningfully averaged over such a class, type or model, since by determining a mean bias
estimate, any instruments that are biased positively will be offset by any that are biased negatively. Because of this,
bias estimate for a class, type or model of densitometer (if determined as a simple arithmetic mean of the bias
estimates determined for individuals of that class, type or model) is of limited (if any) value and should not be
reported. If determined as such an arithmetic mean, it may only be meaningful if that entire class, type or model is
fraught with a systematic design defect. There is currently no agreement as to the most meaningful way to provide
an ISO bias estimate for a class, type or model of densitometer.
The standardized methods for determination of ISO repeatability and ISO stability provide manufacturers with a
uniform basis for stating densitometer performance characteristics as specifications, thereby providing the
customer with the most useful information.
To clarify and provide mutual understanding, a list of definitions applicable to the performance characteristics has
been provided.
INTERNATIONAL STANDARD ISO 14807:2001(E)
Photography — Transmission and reflection densitometers —
Method for determining performance
1 Scope
This International Standard defines a common set of reporting parameters and describes the methods to be used in
the determination and presentation of individual densitometer performance and manufacturer-reported performance
specifications. This International Standard applies to transmission and reflection densitometers typically
manufactured for and used by the photographic, graphic arts and radiographic trades.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 5-1:1984, Photography — Density measurements — Part 1: Terms, symbols and notations
ISO 5-2:2001, Photography — Density measurements — Part 2: Geometric conditions for transmission density
ISO 5-3:1995, Photography — Density measurements — Part 3: Spectral conditions
ISO 5-4:1995, Photography — Density measurements — Part 4: Geometric conditions for reflection density
ISO 554:1976, Standard atmospheres for conditioning and/or testing — Specifications
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
NOTE There are a number of terms that are commonly used in connection with the subject of measurement, such as bias,
repeatability, stability and traceability. One can avoid confusion by using such terms in a way that is consistent with other
international documents. Definitions of many such terms are given in the International Vocabulary of Basic and General Terms
1)
[2]
in Metrology , the title of which is commonly abbreviated, as VIM. The VIM was developed by ISO Technical Advisory
Group4(TAG4).
3.1
true value (of a quantity)
value consistent with the definition of a given particular quantity
NOTE 1 This is a value that would be obtained by a perfect measurement.
1) Throughout this International Standard, raised numbers in square brackets refer to informative documents listed in the
bibliography.
NOTE 2 True values are by nature indeterminate.
NOTE 3 The indefinite article “a”, rather than the definite article “the”, is used in conjunction with “true value” because there
may be many values consistent with the definition of a given particular quantity.
[VIM:1993, 1.19]
3.2
conventional true value (of a quantity)
value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty
appropriate for a given purpose
[VIM:1993, 1.20]
NOTE 1 “Conventional true value” is sometimes called assigned value, best estimate of the value, conventional value or
reference value.
NOTE 2 An assigned value of a certified reference material is one type of conventional true value.
3.3
measurand
particular quantity subject to measurement
EXAMPLE Vapour pressure of a given sample of water at 20 °C.
NOTE The specification of a measurand may require statements about quantities such as time, temperature and pressure.
[VIM:1993, 2.6]
3.4
repeatability (of results of measurements)
closeness of the agreement between the results of successive measurements of the same measurand carried out
under the same conditions of measurement
NOTE 1 These conditions are called repeatability conditions.
NOTE 2 Repeatability conditions include:
� the same measurement procedure
� the same observer
� the same measuring instrument, used under the same conditions
� the same location
� repetition over a short period of time.
NOTE 3 Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results.
[VIM:1993, 3.6]
3.5
experimental standard deviation
s
for a series of n measurements of the same measurand, the quantity s characterizing the dispersion of the results
and given by the formula:
n
xx�
��
i
�
i�1
s �
n�1
2 © ISO 2001 – All rights reserved

x being the result of the ith measurement and x being the arithmetic mean of the n results considered
i
[VIM:1993, 3.8]
3.6
systematic error
mean that would result from an infinite number of measurements of the same measurand carried out under
repeatability conditions minus a true value of the measurand
[VIM:1993, 3.14]
NOTE Like true value, systematic error and its causes cannot be completely known.
3.7
stability
ability of a measuring instrument to maintain constant its metrological characteristics with time
NOTE 1 Where stability with respect to a quantity other than time is considered, this should be stated explicitly.
NOTE 2 Stability may be quantified in several ways, for example:
� in terms of the time over which a metrological characteristic changes by a stated amount, or
� in terms of the change in a characteristic over a stated time.
[VIM:1993, 5.14]
3.8
error (of indication) of a measuring instrument
indication of a measuring instrument minus a true value of the corresponding input quantity
[VIM:1993, 5.20]
3.9
bias (of a measuring instrument)
systematic error of the indication of a measuring instrument
NOTE The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate
number of repeated measurements.
[VIM:1993, 5.25]
3.10
traceability
property of the resu
...