EN ISO 8655-7:2005

SLOVENSKI STANDARD
01-februar-2006
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Piston-operated volumetric apparatus - Part 7: Non-gravimetric methods for the
assessment of equipment performance (ISO 8655-7:2005)
Volumenmessgeräte mit Hubkolben - Teil 7: Nicht-gravimetrische Prüfverfahren zur
Bewertung der Geräteeigenschaften (ISO 8655-7:2005)
Appareils volumétriques a piston - Partie 7: Méthodes non gravimétriques pour
l'estimation de la performance d'équipement (ISO 8655-7:2005)
Ta slovenski standard je istoveten z: EN ISO 8655-7:2005
ICS:
17.060 Merjenje prostornine, mase, Measurement of volume,
gostote, viskoznosti mass, density, viscosity
71.040.20 Laboratorijska posoda in Laboratory ware and related
aparati apparatus
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 8655-7
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2005
ICS 17.060
English Version
Piston-operated volumetric apparatus - Part 7: Non-gravimetric
methods for the assessment of equipment performance (ISO
8655-7:2005)
Appareils volumétriques à piston - Partie 7: Méthodes non Volumenmessgeräte mit Hubkolben - Teil 7: Nicht-
gravimétriques pour l'estimation de la performance gravimetrische Prüfverfahren zur Bewertung der
d'équipement (ISO 8655-7:2005) Geräteeigenschaften (ISO 8655-7:2005)
This European Standard was approved by CEN on 13 August 2005.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8655-7:2005: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 8655-7:2005) has been prepared by Technical Committee ISO/TC 48
"Laboratory glassware and related apparatus" in collaboration with Technical Committee
CEN/TC 332 "Laboratory equipment", the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by March 2006, and conflicting national
standards shall be withdrawn at the latest by March 2006.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 8655-7:2005 has been approved by CEN as EN ISO 8655-7:2005 without any
modifications.
INTERNATIONAL ISO
STANDARD 8655-7
First edition
2005-09-01
Piston-operated volumetric apparatus —
Part 7:
Non-gravimetric methods for the
assessment of equipment performance
Appareils volumétriques à piston —
Partie 7: Méthodes non gravimétriques pour l'estimation de la
performance d'équipement
Reference number
ISO 8655-7:2005(E)
©
ISO 2005
ISO 8655-7:2005(E)
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ii © ISO 2005 – All rights reserved

ISO 8655-7:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Principle. 2
4.1 Photometric method. 2
4.2 Titrimetric method . 2
5 Reagents. 3
5.1 Reagents for photometric method. 3
5.2 Reagents for titrimetric method . 3
6 Apparatus . 4
6.1 Photometric method. 4
6.2 Titrimetric method . 4
7 Test conditions . 5
8 Procedure . 5
8.1 General. 5
8.2 Photometric method. 5
8.3 Titrimetric method . 5
9 Calculation. 6
10 Test report . 6
Annex A (informative) Example 1 for photometric test method . 7
Annex B (informative) Example 2 for photometric test method . 13
Annex C (informative) Example for titration test method. 17
Bibliography . 21

ISO 8655-7:2005(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 8655-7 was prepared by Technical Committee ISO/TC 48, Laboratory glassware and related apparatus,
Subcommittee SC 6, Laboratory and volumetric ware.
ISO 8655 consists of the following parts, under the general title Piston-operated volumetric apparatus:
 Part 1: Terminology, general requirements and user recommendations
 Part 2: Piston pipettes
 Part 3: Piston burettes
 Part 4: Dilutors
 Part 5: Dispensers
 Part 6: Gravimetric methods for the determination of measurement error
 Part 7: Non-gravimetric methods for the assessment of equipment performance
iv © ISO 2005 – All rights reserved

ISO 8655-7:2005(E)
Introduction
The ISO 8655 series was developed in order to specify the differing types of piston-operated volumetric
apparatus and to provide a reference method and alternative test methods for verifying their characteristics
covering the volume range typically from:
 the smallest hand-held pipetting devices, e.g. 1 µl, up to
 the largest laboratory bench-standing volume dispensing instruments, e.g. 100 ml.
ISO 8655-1 provides general requirements and terminology. The detailed volumetric ranges for each type of
apparatus specified in the ISO 8655 series are indicated in the appropriate tables of maximum permissible
error, i.e. for piston pipettes (ISO 8655-2), for piston burettes (ISO 8655-3), for dilutors (ISO 8655-4) and for
dispensers (ISO 8655-5).
ISO 8655-6 is the reference method for type testing and conformity testing. It is gravimetric and contains
precise instructions designed to limit variation in procedure and thereby the potential for sources of error – a
necessity for type and conformity testing.
The photometric and titrimetric methods described in this part of ISO 8655, are deliberately given as outline
methods (see examples in the informative annexes), so that individual laboratories having their own
equipment available, and working to different uncertainty requirements, may adapt either these methods, or
the gravimetric method, accordingly. If the laboratories operate under ISO 9000 series regimes, or have
accreditation to ISO 17025, the individually-adapted methods are usually validated to give results equivalent
to those given by the gravimetric method specified in ISO 8655-6.
This part of ISO 8655 is applicable to the following types of testing:
 of piston-operated volumetric apparatus for purposes other than type testing or the conformity testing
which is required prior to declarations or certification of conformity;
 in user locations, where there may be no suitable balance or facilities to perform the reference method
given in ISO 8655-6, but which may have at their disposal a suitable photometer or automatic titrator.
As users have expressed the wish to have alternative tests available, the following observations are given to
help them select the most appropriate test methods for their purposes.
a) Gravimetric method: Uncertainty values can increase at volumes significantly below 1 µl, due to
increasing balance uncertainty, especially in low humidity areas (where there is increased risk of
evaporation) and due to the effects of static electricity. These effects are compensated for through the
careful design of the test method specified in ISO 8655-6, which applies to the vo
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