FprEN ISO 8655-7

Piston-operated volumetric apparatus - Part 7: Alternative measurement procedures for the determination of volume (ISO/FDIS 8655-7:2021)

This document specifies alternative measurement procedures for the determination of  volume of piston-operated volumetric apparatus.
The procedures are applicable to complete systems comprising the basic apparatus and all parts selected for use with the apparatus, disposable or reusable, involved in the measurement by delivery process (Ex). Methods described in this document are suitable for various maximum nominal volumes of piston-operated volumetric apparatus. It is the responsibility of the user to select the appropriate method.

Volumenmessgeräte mit Hubkolben - Teil 7: Alternatives Prüfverfahren zur Bestimmung des Volumens (ISO/FDIS 8655-7:2021)

Dieses Dokument legt alternative Referenzmessverfahren zur Bestimmung des Volumens von Volumenmessgeräten mit HubkolbenN1) fest.
Die Verfahren gelten für vollständige Gerätesysteme, bestehend aus dem Grundgerät und allen für die Verwendung ausgewählten Zubehörteilen, die mehrfach verwendbar oder für den einmaligen Gebrauch bestimmt sein können; die Dosierung erfolgt durch Abgabevorgänge (Ex). Die in diesem Dokument beschriebenen Verfahren eignen sich für unterschiedliche Höchstnennvolumina von Kolbenhubgeräten. Es liegt in der Verantwortung des Anwenders, das geeignete Verfahren auszuwählen.

Appareils volumétriques à piston - Partie 7: Modes opératoires de mesure alternatifs pour la détermination de volumes (ISO/FDIS 8655-7:2021)

Le présent document spécifie des modes opératoires de mesure alternatifs pour la détermination du volume des appareils volumétriques à piston.
Les modes opératoires sont applicables à des systèmes complets comprenant l’appareil de base et toutes les parties sélectionnées pour être utilisées avec l’appareil, à usage unique ou réutilisables, impliqués dans le mesurage par procédé de distribution (Ex). Les méthodes décrites dans le présent document sont adaptées à différents volumes nominaux maximum d’appareils volumétriques à piston. Il en va de la responsabilité de l’utilisateur de sélectionner la méthode appropriée.

Volumetrične naprave, delujoče na bat - 7. del: Nadomestni merilni postopki za določanje prostornine (ISO/DIS 8655-7:2020)

General Information

• Status: Not Published
• ICS: 17.060 - Measurement of volume, mass, density, viscosity
• ICS: 71.040.20 - Laboratory ware and related apparatus
• Technical Committee: CEN/TC 332 - Laboratory equipment
• Drafting Committee: CEN/TC 332/WG 1 - Glass and plastics devices including volumetric instruments
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Due Date: 13-Feb-2022
• Completion Date: 13-Feb-2022
• Ref Project: kSIST FprEN ISO 8655-7:2020 - Piston-operated volumetric apparatus - Part 7: Alternative measurement procedures for the determination of volume (ISO/DIS 8655-7:2020)

RELATIONS

• Revised: EN ISO 8655-7:2005 - Piston-operated volumetric apparatus - Part 7: Non-gravimetric methods for the assessment of equipment performance (ISO 8655-7:2005)
• Effective Date: 04-Apr-2018
• Revised: EN ISO 8655-7:2005/AC:2009 - Piston-operated volumetric apparatus - Part 7: Non-gravimetric methods for the assessment of equipment performance (ISO 8655-7:2005/Cor 1:2008)
• Effective Date: 04-Apr-2018

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 8655-7:2020
01-oktober-2020
Volumetrične naprave, delujoče na bat - 7. del: Nadomestni merilni postopki za
določanje prostornine (ISO/DIS 8655-7:2020)

Piston-operated volumetric apparatus - Part 7: Alternative measurement procedures for

the determination of volume (ISO/DIS 8655-7:2020)

Volumenmessgeräte mit Hubkolben - Teil 7: Alternatives Prüfverfahren zur Bestimmung

des Volumens (ISO/DIS 8655-7:2020)
Appareils volumétriques à piston - Partie 7: Méthodes non gravimétriques pour
l’estimation de la performance d’équipement (ISO/DIS 8655-7:2020)
Ta slovenski standard je istoveten z: prEN ISO 8655-7
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
oSIST prEN ISO 8655-7:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 8655-7:2020
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oSIST prEN ISO 8655-7:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 8655-7
ISO/TC 48 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-07-29 2020-10-21
Piston-operated volumetric apparatus —
Part 7:
Alternative measurement procedures for the
determination of volume
ICS: 17.060
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 8655-7:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
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oSIST prEN ISO 8655-7:2020
ISO/DIS 8655-7:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
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Published in Switzerland
ii © ISO 2020 – All rights reserved
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oSIST prEN ISO 8655-7:2020
ISO/DIS 8655-7:2020(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 General requirements ..................................................................................................................................................................................... 2

4.1 Metrological confirmation ............................................................................................................................................................ 2

4.2 Operator qualification....................................................................................................................................................................... 2

5 Requirements for testing multi-channel POVA ..................................................................................................................... 3

6 Performance requirements ....................................................................................................................................................................... 3

6.1 Performance tolerances .................................................................................................................................................................. 3

6.2 Operator impact ..................................................................................................................................................................................... 3

7 Test conditions ....................................................................................................................................................................................................... 3

7.1 General ........................................................................................................................................................................................................... 3

7.2 Test equipment ....................................................................................................................................................................................... 3

7.3 Test room, environmental conditions ................................................................................................................................. 4

7.4 Test volumes ............................................................................................................................................................................................. 4

7.4.1 Fixed volume POVA ........................................................................................................................................................ 4

7.4.2 Adjustable volume POVA ........................................................................................................................................... 4

7.5 Number of measurements per test volume .................................................................................................................... 4

7.6 Test liquids.................................................................................................................................................................................................. 5

8 Evaluation .................................................................................................................................................................................................................... 5

8.1 Mean volume............................................................................................................................................................................................. 5

8.2 Systematic error ..................................................................................................................................................................................... 5

8.3 Random error ........................................................................................................................................................................................... 6

9 Test methods ............................................................................................................................................................................................................. 6

9.1 General ........................................................................................................................................................................................................... 6

9.2 Gravimetric method ............................................................................................................................................................................ 7

9.3 Dual-dye ratiometric photometric method .................................................................................................................... 7

9.4 Single dye photometric method ............................................................................................................................................... 7

9.5 Hybrid photometric/gravimetric method for multichannel POVA ............................................................ 7

9.6 Titration method ................................................................................................................................................................................... 8

9.7 Batch testing .............................................................................................................................................................................................. 8

10 Dispense procedures ........................................................................................................................................................................................ 8

10.1 General ........................................................................................................................................................................................................... 8

10.2 Preparation ................................................................................................................................................................................................ 8

10.3 Single-channel air displacement pipettes (in accordance with ISO 8655-2) .................................... 9

10.3.1 General...................................................................................................................................................................................... 9

10.3.2 Test cycle ................................................................................................................................................................................. 9

10.4 Multi-channel pipettes (in accordance with ISO 8655-2) ...............................................................................10

10.5 Positive displacement pipettes (in accordance with ISO 8655-2) ...........................................................10

10.6 Burettes (in accordance with ISO 8655-3) ..................................................................................................................11

10.7 Dilutors (in accordance with ISO 8655-4) ...................................................................................................................11

10.7.1 General...................................................................................................................................................................................11

10.7.2 Test cycle ..............................................................................................................................................................................12

10.8 Dispensers (in accordance with ISO 8655-5) ............................................................................................................12

10.9 Syringes (in accordance with ISO 8655-9) ..................................................................................................................13

10.9.1 General...................................................................................................................................................................................13

10.9.2 Test cycle ..............................................................................................................................................................................13

11 Reporting of results ........................................................................................................................................................................................13

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oSIST prEN ISO 8655-7:2020
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Annex A (normative) Gravimetric procedure ..........................................................................................................................................15

Annex B (normative) Dual-dye ratiometric photometric procedure ...............................................................................20

Annex C (normative) Single dye photometric procedure .............................................................................................................27

Annex D (normative) Photometric/gravimetric hybrid procedure ..................................................................................31

Annex E (normative) Titrimetric procedure .............................................................................................................................................40

Annex F (normative) Conversion of liquid mass to volume .......................................................................................................44

Bibliography .............................................................................................................................................................................................................................47

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oSIST prEN ISO 8655-7:2020
ISO/DIS 8655-7:2020(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 48, Laboratory Equipment, Working

Group WG 04, Piston-operated instruments.

This second edition cancels and replaces the first edition (ISO 8655-7:2005 and ISO 8655-7:2005/Cor

1:2008), which has been technically revised.
The main changes compared to the previous edition are as follows:
— a gravimetric test method was added (Clause 9.2);
— a photometric/gravimetric hybrid test method was added (Clause 9.5);
— a batch testing method was added (Clause 9.7);
— measurement procedures for all methods are given in normative Annexes A to E;

— standard dispense procedures for POVA described in ISO 8655-2, −3, −4, −5, and −9 were added

(Clause 10);
— requirements for operator qualification have been added (Clause 4.2);

— requirements for testing of multi-channel POVA is described in more detail, with specific procedures

given for these apparatus (Clauses 5, 9.5, and Annex D);
— Annexes A, B, and C of the first edition have been deleted and replaced.
A list of all parts in the ISO 8655 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
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oSIST prEN ISO 8655-7:2020
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Introduction
ISO 8655 addresses the needs of:

— manufacturers, as a basis for quality control including, where appropriate, the issuance of

manufacturer’s declarations;

— calibration laboratories, test houses, users of the equipment and other bodies as a basis for

independent calibration, certification, and routine checking.

The tests specified in the ISO 8655 series are intended to be carried out by trained personnel.

vi © ISO 2020 – All rights reserved
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oSIST prEN ISO 8655-7:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 8655-7:2020(E)
Piston-operated volumetric apparatus —
Part 7:
Alternative measurement procedures for the
determination of volume
1 Scope

This part of ISO 8655 specifies alternative measurement procedures for the determination of volume of

piston-operated volumetric apparatus.

The tests are applicable to complete systems comprising the basic apparatus and all parts selected

for use with the apparatus, disposable or reusable, involved in the measurement by delivery process

(Ex). Methods described in this part of ISO 8655 are suitable for various maximum nominal volumes of

piston-operated volumetric apparatus. The user of this standard shall ensure that the selected method

is suitable for its intended purpose.

NOTE General requirements and definitions of terms for piston-operated volumetric apparatus are given

in ISO 8655-1. For the metrological requirements, maximum permissible errors, requirements for marking and

information to be provided for users for piston-operated volumetric apparatus, see ISO 8655-2 for pipettes,

see ISO 8655-3 for burettes, see ISO 8655-4 for dilutors, see ISO 8655-5 for dispensers, and see ISO 8655-9 for

manually operated precision laboratory syringes. The gravimetric reference measurement procedure for the

determination of volume is given in ISO 8655-6. The photometric reference measurement procedure for the

determination of volume is given in ISO 8655-8.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 3696:1987, Water for analytical laboratory use — Specification and test methods

ISO/DIS 8655-1:2020, Piston-operated volumetric apparatus — Part 1: Terminology, general requirements

and user recommendations

ISO/DIS 8655-2, 2022, Piston-operated volumetric apparatus — Part 2: Piston pipettes

ISO/DIS 8655-3:2020, Piston-operated volumetric apparatus — Part 3: Piston burettes

ISO/DIS 8655-4:2020, Piston-operated volumetric apparatus — Part 4: Dilutors
ISO/DIS 8655-5:2020, Piston-operated volumetric apparatus — Part 5: Dispensers

ISO/DIS 8655-6:2020, Piston-operated volumetric apparatus — Part 6: Gravimetric reference measurement

procedure for the determination of volume

ISO/DIS 8655-8:2020, Piston-operated volumetric apparatus — Part 8: Photometric reference

measurement procedure for the determination of volume

ISO/DIS 8655-9:2020, Piston-operated volumetric apparatus — Part 9: Manually operated precision

laboratory syringes

ISO/TR 16153, Piston-operated volumetric instruments — Determination of uncertainty for volume

measurements made using the photometric method
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oSIST prEN ISO 8655-7:2020
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ISO/TR 20461, Determination of uncertainty for volume measurements made using the gravimetric method

ISO/IEC Guide 2, Standardization and related activities — General vocabulary

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

me a s ur ement (GUM: 1995)

ISO/IEC Guide 98-4:2012, Uncertainty of measurement — Part 4: Role of measurement uncertainty in

conformity assessment

ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and

associated terms (VIM)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/DIS 8655-1:2020,

ISO/IEC Guide 2, and ISO/IEC Guide 99 apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
acceptance quality limit
AQL
worst tolerable quality level

Note 1 to entry: This concept only applies when a sampling scheme with rules for switching and for

discontinuation, such as in ISO 2859-1, ISO 3951-1 or ISO 3951-5 is used.

Note 2 to entry: Although individual lots with quality as bad as the acceptance quality limit may be accepted

with fairly high probability, the designation of an acceptance quality limit does not suggest that this is a desirable

quality level. Sampling schemes found in International Standards such as ISO 2859-1, ISO 3951-1 or ISO 3951-5,

with their rules for switching and for discontinuation of sampling inspection, are designed to encourage suppliers

to have process averages consistently better than the AQL.
[SOURCE: ISO 3951-5:2006, 3.6 – modified: shortened Note 2 to entry.]
4 General requirements
4.1 Metrological confirmation

Metrological confirmation of all POVA shall be performed on a regular basis to ensure the apparatus

conforms to requirements for its intended use. The requirements of the methods and procedures

described in this International Standard are suitable to be used for metrological confirmation of POVA.

For calibrations, the procedure of this International Standard shall be validated by comparison to one

of the reference measurement procedures described in ISO 8655-6 or ISO 8655-8.
4.2 Operator qualification

An operator who uses, calibrates, or tests POVA shall be adequately trained on the use of the type of

POVA under test. Operator training and competence should be documented.

NOTE It is worth considering the qualification of operators with previously calibrated pipettes.

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5 Requirements for testing multi-channel POVA

Metrological confirmation of multi-channel POVA shall test the performance of each channel of a multi-

channel POVA by calibration and routine tests on a regular basis. Not testing each channel can leave the

user exposed to significant risk of error.

Test liquid should be aspirated simultaneously with all channels of a multi-channel POVA, as described

in ISO 8655-2. If liquid is aspirated in one channel only, this fact shall be reported within the test report.

Depending on the selected test method and available measurement equipment, it might be necessary to

test each channel individually in successive tests.

NOTE 1 Using a test method based on volume measurements in a microplate allows for simultaneous

dispensing of the test liquid from all channels into the microplate. Annex D provides a procedure for calibrating

multi-channel pipettes.
NOTE 2 Consistent and even tip fitting is important and can impact performance.

NOTE 3 Channel to channel variation can be exaggerated by poor quality tips. Differences in dimensions will

lead to inconsistent aspiration and delivery.
6 Performance requirements
6.1 Performance tolerances

Calibration and routine test results may be reported without comparison to performance tolerances.

If the results are verified against performance tolerances, these tolerances shall be agreed upon with

the user.

Performance tolerances may be based on the user’s liquid handling process tolerances or the

product tolerances given in the part of ISO 8655 corresponding to the type of POVA under test or the

manufacturers tolerances, subject to them being fit for purpose.
6.2 Operator impact

Measurement of volumetric performance includes random and systematic errors of the POVA, as well as

errors introduced by the device’s operator. Performance tolerances for POVA shall include the operator

error component as well, where applicable.

NOTE The performance of a hand-held pipette is inseparable from the performance of its operator.

7 Test conditions
7.1 General

Test conditions described in this clause shall be validated for their suitability for the selected test

method and procedure. Test conditions, together with the test equipment and detailed test procedure,

impact the uncertainty of measurement. Examples for the calculation of the expanded uncertainty of

the mean volume and of the uncertainty in use of a single delivered volume are given in ISO/TR 16153

and ISO/TR 20461.
7.2 Test equipment

All equipment used for the testing of POVA, including for the preparation of test solutions, shall be

chosen such that the required uncertainty of measurement can be obtained.

All test equipment used shall be of suitable readability, accuracy, reproducibility and stability, consistent

with the required expanded uncertainty of measurement.
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oSIST prEN ISO 8655-7:2020
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Deviations from the test equipment given in this standard shall be taken into account when calculating

the expanded measurement uncertainty and shall be proven to yield measurement results fit for the

intended purpose.
7.3 Test room, environmental conditions

The test room should be kept at a steady temperature throughout the entirety of the equilibration time

for the test equipment and POVA (± 1 °C), and throughout the POVA testing time (± 0,5 °C). All test

equipment, POVA, exchangeable parts (e.g. pipette tips), and reagents used shall be equilibrated to the

test room temperature.

The ambient temperature, relative humidity, and barometric pressure at the time of the test shall be

recorded.

To evaluate a POVA’s fitness for purpose, the test room conditions should reflect the environmental

conditions under which the POVA is used. This can generally be achieved when a POVA is calibrated

within the laboratory in which it is used.

NOTE Calibration laboratories at test houses or pipette manufacturer’s quality control laboratories can often

precisely control environmental conditions to achieve a desired standard condition. It can be very challenging to

reproduce such results under different environmental conditions.
7.4 Test volumes
7.4.1 Fixed volume POVA

In the case of a fixed-volume POVA, the selected volume V is the nominal volume V and is the only

S 0
test volume.
7.4.2 Adjustable volume POVA

a) For calibrations, adjustable volume POVA shall be tested at least at three volumes:

— nominal volume,

— 50 % of the nominal volume, or the closest possible (if equidistant, use the higher value);

— the lower limit of the useable volume range or 10 % of the nominal volume (whichever is the

greater).
Measurement of further volumes is optional.
b) For routine tests, fewer than three volumes may be tested.

In case the POVA is to be tested at only two volumes, the nominal volume and the lower limit of the

useable volume range, or 10% of the nominal volume (whichever is the greater), shall be tested.

NOTE The linearity of delivered volumes between these two test points is unknown and leaves the user with

increased risk for volumetric errors as compared to a test at three volumes.

In case the POVA is tested only at one volume, it shall be tested at its nominal volume, or at the volume

at which it will be used.
7.5 Number of measurements per test volume

The confidence of metrological confirmation increases with the number of replicate measurements

for each test volume. A minimum of ten measurements per volume are required by the reference

measurement procedures of ISO 8655-6 and ISO 8655-8. For the test procedures of this International

Standard, ten measurements are encouraged, but fewer replicate measurements may be made if the

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expanded uncertainty of measurement for the POVA is fit for the intended pu
...