1 Scope

2 Normative references

3 Terms and definitions

4 Principle

5 Volume and reference temperature

5.1 Unit of volume

5.2 Reference temperature

6 Apparatus and calibration liquid

6.1 Balance

6.2 Measurement devices

6.3 Calibration liquid

6.4 Receiving vessel

7 Factors affecting the accuracy of volumetric instruments

7.1 General

7.2 Temperature

7.2.1 Temperature of the volumetric instrument

7.2.2 Temperature of calibration liquid

7.3 Cleanliness of surface

7.4 Conditions of used volumetric instruments

7.5 Delivery time and waiting time

8 Setting the meniscus

8.1 General

8.2 Setting the meniscus

8.2.1 Meniscus of transparent liquids

8.2.2 Meniscus of opaque liquids

9 Calibration procedure

9.1 General

9.2 Test room

9.3 Filling and delivery

9.3.1 Volumetric flasks and measuring cylinders

9.3.2 Pipettes adjusted to deliver

9.3.3 Pipettes adjusted to contain

9.3.4 Burettes adjusted to deliver

9.3.5 Pycnometers

9.4 Weighing

9.5 Volume and uncertainty calculation

10 Procedure for use

10.1 General

10.2 Volumetric flasks (in accordance with ISO 1042 or ISO 5215)

10.3 Measuring cylinders (in accordance with ISO 4788 or ISO 6706)

10.4 Burettes (in accordance with ISO 385)

10.5 Pipettes

10.5.1 Pipettes adjusted to deliver (see ISO 648 and ISO 835, or other pipettes, e.g. plastic ones)

10.5.2 Pipettes adjusted to contain

10.6 Pycnometers

Annex A (informative) Cleaning of volumetric glassware

Annex B (informative) Cleaning of volumetric plasticware

Annex C (normative) Calculation formulae and tables

Annex D (informative) Coefficient of cubic thermal expansion

Annex E (informative) Uncertainty estimation and repeatability calculation

Bibliography

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ISO 4787:2021(en)

	International Standard ISO 4787
Laboratory glass and plastic ware — Volumetric instruments — Methods for testing of capacity and for use Verrerie et matériel en plastique de laboratoire — Instruments volumétriques — Méthodes d'essai de la capacité et d'utilisation Reference number ISO 4787:2021(en)	Third edition 2021-11 © ISO 2021

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ISO 4787:2021(en)

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.

ISO copyright office

CP 401 • Ch. de Blandonnet 8

CH-1214 Vernier, Geneva

Tel. + 41 22 749 01 11

E-mail copyright@iso.org

Website www.iso.org

Published in Switzerland

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ContentsPage

Foreword

Introduction

1 Scope

2 Normative references

3 Terms and definitions

4 Principle

5 Volume and reference temperature

5.1 Unit of volume

5.2 Reference temperature

6 Apparatus and calibration liquid

6.1 Balance

6.2 Measurement devices

6.3 Calibration liquid

6.4 Receiving vessel

7 Factors affecting the accuracy of volumetric instruments

7.1 General

7.2 Temperature

7.2.1 Temperature of the volumetric instrument

7.2.2 Temperature of calibration liquid

7.3 Cleanliness of surface

7.4 Conditions of used volumetric instruments

7.5 Delivery time and waiting time

8 Setting the meniscus

8.1 General

8.2 Setting the meniscus

8.2.1 Meniscus of transparent liquids

8.2.2 Meniscus of opaque liquids

9 Calibration procedure

9.1 General

9.2 Test room

9.3 Filling and delivery

9.3.1 Volumetric flasks and measuring cylinders

9.3.2 Pipettes adjusted to deliver

9.3.3 Pipettes adjusted to contain

9.3.4 Burettes adjusted to deliver

9.3.5 Pycnometers

9.4 Weighing

9.5 Volume and uncertainty calculation

10 Procedure for use

10.1 General

10.2 Volumetric flasks (in accordance with ISO 1042 or ISO 5215)

10.3 Measuring cylinders (in accordance with ISO 4788 or ISO 6706)

10.4 Burettes (in accordance with ISO 385)

10.5 Pipettes

10.5.1 Pipettes adjusted to deliver (see ISO 648 and ISO 835, or other pipettes, e.g. plastic ones)

10.5.2 Pipettes adjusted to contain

10.6 Pycnometers

Annex A (informative) Cleaning of volumetric glassware

Annex B (informative) Cleaning of volumetric plasticware

Annex C (normative) Calculation formulae and tables

Annex D (informative) Coefficient of cubic thermal expansion

Annex E (informative) Uncertainty estimation and repeatability calculation

Bibliography

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 of 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 www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 48, Laboratory equipment, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 332, Laboratory equipment, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 4787:2010), which has been technically revised.

The main changes compared to the previous edition are as follows:

volumetric plastic ware has been included;

new information on meniscus adjustment of convex meniscus has been added; namely, altered procedure “Upper edge of the graduation line is horizontally tangential to the highest point of meniscus” as compared to older procedure “Upper edge of the graduation line is horizontally tangential to the lowest point of the meniscus”;

improved figures for meniscus adjustment have been provided;

Table 1 has been improved;

new Table 2 for minimum requirements for the measurement devices has been added;

new test room ambient conditions have been added;

new information regarding repeatability and uncertainty has been added in Annex E;

Formula (C.1) has been changed to Formula (1).

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.

Introduction

The International Standards for the individual volumetric instruments include clauses on the specification of capacity (volume); these clauses describe the method of manipulation in sufficient detail to determine the capacity without ambiguity. This document contains supplementary information.

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ISO 4787:2021(en)

International StandardISO 4787:2021(en)

Laboratory glass and plastic ware — Volumetric instruments — Methods for testing of capacity and for use

1Scope

This document provides methods for the testing, calibration and use of volumetric instruments made from glass and plastic in order to obtain the best accuracy in use.

NOTETesting is the process by which the conformity of the individual volumetric instrument with the appropriate standard is determined, resulting in the determination of its error of measurement at one or more points.

This document is applicable to volumetric instruments with nominal capacities in the range of 100 µl to 10 000 ml. These include single-volume pipettes (see ISO 648), graduated pipettes (see ISO 835), burettes (see ISO 385), volumetric flasks (see ISO 1042 and ISO 5215), and graduated measuring cylinders (see ISO 4788 and ISO 6706).

The methods are not intended for testing of volumetric instruments with capacities below 100 µl such as micro-glassware.

This document does not deal specifically with pycnometers as specified in ISO 3507. However, the procedures specified for the determination of volume of glassware can, for the most part, also be followed for the determination of a pycnometer volume. For some types of pycnometers, special handling can be necessary.

2Normative 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 385, Laboratory glassware — Burettes

ISO 648, Laboratory glassware — Single-volume pipettes

ISO 835, Laboratory glassware — Graduated pipettes

ISO 1042, Laboratory glassware — One-mark volumetric flasks

ISO 1773, Laboratory glassware — Narrow-necked boiling flasks

ISO 3507, Laboratory glassware — Pyknometers

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

ISO 4788, Laboratory glassware — Graduated measuring cylinders

ISO 4797, Laboratory glassware — Boiling flasks with conical ground joints

ISO 52151, Laboratory plastic ware — Volumetric flasks

ISO 6706, Plastics laboratory ware — Graduated measuring cylinders

ISO 24450, Laboratory glassware — Wide-necked boiling flasks

ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated terms (VIM)

3Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/IEC Guide 99 apply.

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

—

ISO Online browsing platform: available at https://www.iso.org/obp

—

IEC Electropedia: available at https://www.electropedia.org/

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Bibliography

[1]		EURAMET cg-18 Version 4.0, Guidelines on the calibration of non-automatic weighing instruments
[2]		OIML D 28, Conventional value of the result of weighing in air (Revision of OIML R 33)
[3]		TANAKA M., GIRARD, G., DAVIS, R., PEUTO, A. and BIGNELL, N. Recommended table for the density of water between 0 °C and 40 °C based on recent experimental reports. Metrologia, 38, 2001, pp. 301-309
[4]		EURAMET cg-19 Version 3.0, Guidelines on the determination of uncertainty in gravimetric volume calibration
[5]		A. PICARD R.S. DAVIS, M. GLASER and K FUJII, Revised formula for the density of moist air, Metrologia, 2008, Vol. 45, p. 149-145
[6]		ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)
[7]		NISTIR 7383, Selected procedures for volumetric calibrations (2019)
[8]		ISO 384, Laboratory glass and plastics ware — Principles of design and construction of volumetric instruments

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ICS 17.060; 17.060 Price based on 21 pages © ISO 2021All rights reserved	iso.org

1 Under preparation. Stage at the time of publication: ISO/DIS 5215:2021.