IEC 60734:2012

Household electrical appliances - Performance - Water for testing

IEC 60734:2012 describes the preparation of four types of water of different hardness, conductivity and alkalinity, intended to be used for testing the performance of household appliances such as washing machines, dishwashers, tumble dryers, steam irons etc. It defines the characteristics of these waters and establishes various methods to be used for obtaining them. It also includes specifications for required measurements.

Appareils électrodomestiques - Aptitude à la fonction - Eau pour les essais

La CEI 60734:2012 décrit la préparation de quatre types d'eau de dureté, de conductivité et d'alcalinité différentes, destinés à être utilisés pour les essais de l'aptitude à la fonction des appareils domestiques tels que les machines à laver, les lave-vaisselle, les sèche-linge, les fers à repasser à vapeur, etc. Elle définit les caractéristiques de ces eaux et établit diverses méthodes à utiliser en vue de les obtenir. Elle inclut également des spécifications relatives aux mesures exigées.

General Information

• Status: Published
• Publication Date: 26-Jun-2012
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 97.060 - Laundry appliances
• Technical Committee: SC 59D - Performance of household and similar electrical laundry appliances
• Current Stage: PPUB - Publication issued
• Start Date: 27-Jun-2012
• Completion Date: 27-Jun-2012

Standards Content (sample)

IEC 60734
Edition 4.0 2012-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household electrical appliances – Performance – Water for testing
Appareils électrodomestiques – Aptitude à la fonction – Eau pour les essais
IEC 60734:2012
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IEC 60734
Edition 4.0 2012-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household electrical appliances – Performance – Water for testing
Appareils électrodomestiques – Aptitude à la fonction – Eau pour les essais
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX N
ICS 97.060 ISBN 978-2-83220-139-8

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 60734 © IEC:2012
CONTENTS

FOREWORD ........................................................................................................................... 3

INTRODUCTION ..................................................................................................................... 5

1 Scope ............................................................................................................................... 6

2 Normative references ....................................................................................................... 6

3 Terms, definitions and symbols ........................................................................................ 6

3.1 Terms and definitions .............................................................................................. 6

3.2 Symbols .................................................................................................................. 7

4 Measurements and accuracy ............................................................................................ 8

5 Standard water ................................................................................................................. 8

5.1 Water types ............................................................................................................. 8

5.2 Additional requirements ........................................................................................... 9

6 Preparation of standard water........................................................................................... 9

6.1 Demineralisation of natural water ............................................................................ 9

6.2 Preparation of standard water method B .................................................................. 9

6.2.1 Principle ...................................................................................................... 9

6.2.2 Procedure .................................................................................................... 9

6.2.3 Composition of standard water prepared by method B ............................... 10

6.3 Preparation of water methods C1 and C2 .............................................................. 10

6.3.1 Principle .................................................................................................... 10

6.3.2 Composition of standard water prepared by methods C1 and C2 ............... 10

6.3.3 Hardness adjustment method C1 ............................................................... 11

6.3.4 Hardness adjustment method C2 ............................................................... 11

6.4 Preparation of water method C3 ............................................................................ 11

6.4.1 Principle .................................................................................................... 11

6.4.2 Determination of initial water properties ..................................................... 11

6.4.3 Dilution with demineralised water .............................................................. 11

6.4.4 Determination of the required salt additions ............................................... 12

6.4.5 Adjusting PH ............................................................................................. 13

7 Storage of standard water .............................................................................................. 13

7.1 General ................................................................................................................. 13

7.2 Effects of heat on standard water .......................................................................... 13

8 Checking ........................................................................................................................ 13

Annex A (informative) Water hardness – Conversion table ................................................... 14

Table 1 – Measurement specifications .................................................................................... 8

Table 2 – Composition of soft, medium hard, hard and very hard water .................................. 8

Table 3 – Maximum content of heavy metal ions and chloride ................................................. 9

Table 4 – Amounts of salt solutions to be added to 1 l of demineralised water ...................... 10

Table 5 – Expected composition of standard water achieved by method B ............................ 10

Table A.1 – Conversion in French, English, German degrees and grains per gallon

(US) for the values of specified total hardness ...................................................................... 14

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60734 © IEC:2012 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD ELECTRICAL APPLIANCES –
PERFORMANCE – WATER FOR TESTING
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

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services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

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Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International standard IEC 60734 has been prepared by subcommittee 59D: Home laundry

appliances, of IEC Technical Committee 59: Performance of household and similar electrical

appliances.

This fourth edition cancels and replaces the third edition published in 2001. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) four types of standard water, from soft to very hard, are defined with specification for

hardness, alkalinity and conductivity;
b) preparation method A is no longer maintained; and

c) method C3 is added to prepare water of specified hardness, conductivity and alkalinity

starting with natural water while the natural water based methods C1 and C2 focus on

water hardness only, without allowing control or setting of alkalinity and conductivity.

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– 4 – 60734 © IEC:2012
The text of this standard is based on the following documents:
FDIS Report on voting
59/398/FDIS 59/399/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

Words in bold in the text are defined in Clause 3.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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60734 © IEC:2012 – 5 –
INTRODUCTION

This publication specifies water qualities with regard to hardness, alkalinity and conductivity

and describes several methods to prepare water to be used for testing household appliances

in cases where the water quality is important for the reproducibility of the test results. The

described methods allow the preparation of water complying with all three target requirements

(hardness, alkalinity, conductivity), or just hardness – depending on the requirements set

out in the referring appliance test method.

Compared to the third edition of IEC 60734 (2001), method A is no longer maintained and

another method, method C3, is added.

Method B is used to prepare water of the correct total hardness. Preparation starts with

demineralised water in which hardening salts are dissolved. It will give water specified

temporary as well as permanent hardness, whilst complying with the specifications for

alkalinity and conductivity.

Method C1 starts with natural water with higher hardness than required, while method C2

starts with soft natural water, which is hardened. Depending on the composition of the natural

water, several other ions might be present. Restrictions regarding the amounts are given for

some ions, which may influence the cleaning results when testing washing machines and

dishwashers. No specification regarding temporary and permanent hardness is given.

The development of method C3 appreciates the need for water of specified conductivity and

alkalinity for testing the performance of tumble dryers. While synthetic method B meets this

need, the natural water based methods C1 and C2 focus on water hardness only without

allowing control or setting of alkalinity and conductivity. The new method C3, which starts

with natural water, fills that gap.
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– 6 – 60734 © IEC:2012
HOUSEHOLD ELECTRICAL APPLIANCES –
PERFORMANCE – WATER FOR TESTING
1 Scope

This International Standard describes the preparation of four types of water of different

hardness, conductivity and alkalinity, intended to be used for testing the performance of

household appliances such as washing machines, dishwashers, tumble dryers, steam irons

etc.

It defines the characteristics of these waters and establishes various methods to be used for

obtaining them. It also includes specifications for required measurements.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and

are indispensable for its application. For dated references, only the edition cited applies. For

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

ISO 6059, Water quality – Determination of the sum of calcium and magnesium – EDTA

titrimetric method
ISO 7888, Water quality – Determination of electrical conductivity

ISO 9963-1, Water quality – Determination of alkalinity – Part 1: Determination of total and

composite alkalinity
ISO 10523, Water quality – Determination of pH
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following definitions apply.
3.1.1
water hardness

parameter indicating the quantity of alkaline earth salts (bicarbonates, sulphates, chlorides

etc.) present in the water
3.1.2
total hardness
sum of calcium and magnesium ions in the water
3.1.3
temporary hardness
fraction of the total hardness equivalent to the bicarbonate content
3.1.4
permanent hardness
difference between the total hardness and the temporary hardness
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60734 © IEC:2012 – 7 –
3.1.5
alkalinity

ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate,

i.e. equals the stoichiometric sum of the bases in the solution
3.1.6
conductivity

ability of a solution to conduct an electric current, i.e. measure of the stoichiometric sum of

the ions dissolved in the solution
3.2 Symbols
Symbol Unit Definition
A mmol/l initial alkalinity
A mmol/l target alkalinity
req
c (Fe) mg/l initial iron content
c (Fe) mg/l maximum iron content
max
c (Cu) mg/l initial copper content
c (Cu) mg/l maximum copper content
max
c (Mn) mg/l initial manganese content
c (Mn) mg/l maximum manganese content
max
c (Cl ) mmol/l initial chloride content
c (Cl ) mmol/l maximum chloride content
max
cond initial conductivity
µS/cm
cond target conductivity
µS/cm
req
dil – dilution factor
dil – lowest possible dilution factor that allows the preparation of
min
water to meet all requirements
dil – lowest possible dilution factor that allows the preparation of
min(h,A,cond)
water to meet the total hardness, alkalinity and
conductivity requirements
dil – lowest possible dilution factor that allows the preparation of
min(Fe)
water to meet the maximum iron content requirement
dil – lowest possible dilution factor that allows the preparation of
min(Cu)
water to meet the maximum copper content requirement
dil – lowest possible dilution factor that allows the preparation of
min(Mn)
water to meet the maximum manganese content
requirement
dil – lowest possible dilution factor that allows the preparation of
min(Cl-)
water to meet the maximum chloride content requirement
k – constants
k – constants
h initial total hardness
h target total hardness
req
addition ml quantity of solution to be added to reach required
alkalinity
addition ml quantity of solution to be added to reach required total
hardness
addition ml quantity of solution to be added to reach required
cond
conductivity
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– 8 – 60734 © IEC:2012
4 Measurements and accuracy

Measurements according to this International Standard shall comply with the following

specifications in Table 1:
Table 1 – Measurement specifications
Parameter Unit Minimum Additional requirements and remarks
accuracy
Total hardness mmol/l See ISO 6059 for specifications of such determination.
± 2 %
Alkalinity mmol/l The alkalinity is measured as the concentration of (HCO ). If
± 5 %
determined by titration with hydrochloric acid the endpoint shall
be pH 4,5 – the stoichiometric factor then is 1.
See ISO 9963-1 for specifications of such determination.
Conductivity
µS/cm ± 5 % See ISO 7888 for specifications of such determination.
at 20 °C
pH - The accuracy requirement shall be met over a temperature
± 0,05
range of 15 °C to 25 °C.
See ISO 10523 for specifications of such determination.

Content of iron, copper, - - The requirements for these parameters are maximum content

manganese or chloride requirements. The accuracy of the measurement shall be
sufficient to prove compliance with these requirements.
5 Standard water
5.1 Water types

In Table 2, different water types are defined, which are all referred to by their level of total

hardness and specified with specific levels of total hardness, alkalinity, conductivity and

pH.
Table 2 – Composition of soft, medium hard, hard and very hard water
Water type
Standard
Property Unit
Standard soft Standard hard Standard very
medium hard
water water hard water
water
mmol/l
0,50 1,50 2,50 3,50
Total hardness
2+ 2+ ± 0,20 ± 0,20 ± 0,20 ± 0,20
(Ca /Mg )
mmol/l
0,67 2,00 3,35 4,70
Alkalinity
± 0,20 ± 0,20 ± 0,20 ± 0,20
(HCO )
Conductivity 150 450 750 1050
µS/cm
(at 20 °C) ± 50 ± 100 ± 150 ± 250
- 8,0 to 8,5 7,5 to 7,9 7,3 to 7,7 -
(at 20 °C)

Other test methods and standards referring to the water types in this International Standard

may require to meet all or only selected properties given in Table 2.

NOTE With the specification of these four standard waters it is possible to select one or more standardised

waters, which would approximate the local natural waters available. If any other water hardness is needed, it can

be prepared in a similar way by interpolation of the given specifications.
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60734 © IEC:2012 – 9 –
5.2 Additional requirements

Other test methods and standards referring to the water types described in this International

Standard may also require that any or all of the specifications shown in Table 3 are met.

Table 3 – Maximum content of heavy metal ions and chloride
Water type
Standard Standard
Property Unit
Standard Standard
medium hard very hard
soft water hard water
water water
Max. iron content, c (Fe) mg/l 0,1
max
Max. copper content, c (Cu) mg/l 0,05
max
Max. manganese content, c (Mn) mg/l 0,05
max
Not
Max. chloride content, c (Cl ) mmol/l 4,5
max
applicable

NOTE Iron, copper and manganese can influence bleach performance if the water is used for cleaning

purposes. The chloride content may be of relevance for testing dishwashers. Standard very hard water does not

meet the chloride content requirement.
6 Preparation of standard water
6.1 Demineralisation of natural water

Natural water is demineralised so that its specific resistance is 100 000 Ω/cm or more (i.e. its

conductivity is 10 μS/cm at maximum). Water of this quality can be obtained e.g. using

mixed cation and anion exchange resins or by reverse osmosis.

When an ion exchange resin is new, the first one or two preparations should be discarded.

This is not necessary after each normal regeneration.
6.2 Preparation of standard water method B
6.2.1 Principle

This preparation method starts with demineralised water to which salts are added to achieve

the specified water properties.
6.2.2 Procedure
Prepare the following solutions of salts in demineralised water:
− Solution 1 NaHCO 67,2 g/l (800 mmol/l)
− Solution 2 MgSO · 7H O 38,0 g/l (154,2 mmol/l)
4 2
− Solution 3 CaCl ·2H O 65,6 g/l (446,1 mmol/l)
2 2

Add specified amounts of the three solutions as given in Table 4 to 0,7 l of demineralised

water and add up to 1,0 l for preparation of the desired standard water. If large amounts of

water are prepared, the addition may be performed through automatic dosage. Finally, adjust

the pH to the range specified in Table 2 with HCl or NaOH before use.
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– 10 – 60734 © IEC:2012
Table 4 – Amounts of salt solutions to be added to 1 l of demineralised water
Water type
Solution
Standard soft Standard medium Standard hard Standard very
water hard water water hard water
Solution 1
0,83 ml 2,50 ml 4,17 ml 5,84 ml
(NaHCO )
Solution 2
0,83 ml 2,50 ml 4,17 ml 5,84 ml
(MgSO ·7H O)
4 2
Solution 3
0,83 ml 2,50 ml 4,17 ml 5,84 ml
(CaCl ·2H O)
2 2
6.2.3 Composition of standard water prepared by method B
The temporary hardness component of the water consists of calcium and magnesium
hydrogen carbonates Ca(HCO ) and Mg(HCO ) . The permanent hardness component
3 2 3 2

consists of the chlorides and sulphates of calcium and magnesium (CaCl , CaSO , MgCl ,

2 4 2
MgSO ). Composition of standard water achieved by method B is shown in Table 5.
Table 5 – Expected composition of standard water achieved by method B
Water type
Standard soft Standard Standard hard Standard very
water medium hard water hard water
Ions Mol. weight
water
Ion concentrations
(mmol/l)
Ca 40,0 0,37 1,11 1,85 2,59
Mg 24,3 0,13 0,39 0,65 0,91
HCO 61,0 0,67 2,00 3,35 4,68
Cl 35,5 0,75 2,23 3,75 5,23
SO 96,0 0,13 0,39 0,65 0,91
Na 23,0 0,67 2,00 3,35 4,68
Temporary hardness (mmol/l) 0,33 1,00 1,67 2,34
6.3 Preparation of water methods C1 and C2
6.3.1 Principle

Methods C1 and C2 allow to prepare standard water of specified total hardness starting with

natural water. Methods C1 and C2 do not adjust alkalinity or conductivity.
6.3.2 Composition of standard water prepared by methods C1 and C2

If the test method or standard referring to the water types in this standard also requires any or

all of the specifications of Table 3 to be met (maximum content of heavy metals and chloride),

the natural water shall be analyzed regarding the respective (required) properties. If the

content of iron, copper, manganese or chloride in the natural water exceeds the limits

specified in 5.2, first dilute the natural water with demineralised water.

No differentiation is made between temporary hardness and permanent hardness. The

2+ 2+
Ca /Mg ratio shall be 1,5 to 9.
---------------------- Page: 12 ----------------------
60734 © IEC:2012 – 11 –

The hardness of the natural water is analyzed for its calcium and magnesium content. If the

calcium/magnesium ratio is outside the limits, adjustments are made by dissolving some of

the missing ions in the form of calcium chloride (CaCl ·2H O) or magnesium sulphate

2 2
(MgSO ·7 H O).
4 2
6.3.3 Hardness adjustment method C1

Method C1 is used if the adjusted natural water is harder than the required total hardness.

Some of the natural water is softened by replacing calcium and magnesium against sodium by

means of a cation exchange resin or by use of demineralised water for dilution. If the pH is

too low, some CO shall be removed by air bubbling.
6.3.4 Hardness adjustment method C2

Method C2 is used if the natural water is too soft. The soft natural water is mixed with calcium

and magnesium salts in such a way that the required hardness is obtained.
6.4 Preparation of water method C3
6.4.1 Principle

Method C3 allows to prepare standard water of specified total hardness, alkalinity and

conductivity starting with natural water.
6.4.2 Determination of initial water properties

The natural water shall be analyzed regarding total hardness h , alkalinity A and

0 0
conductivity cond .

If the test method or standard referring to the water types in this standard also requires any or

all of the specifications of Table 3 to be met (maximum content of heavy metals and chloride),

the natural water shall additionally be analyzed regarding the respective (required) properties:

c (Fe), c (Cu), c (Mn), c (Cl )
0 0 0 0
6.4.3 Dilution with demineralised water
6.4.3.1 Determination of the dilution factor

With the determined values for initial total hardness h , alkalinity A and conductivity cond

0 0 0

and the target values for these measures, a minimum dilution factor dil for these

min (h,A,cond)
parameters can be calculated as:
cond − k A − k h
0 A 0 H 0
dil =
min (h,A,cond)
cond − k A − k h
req A req H req
with k and k being the following constants:
A H
...