This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 23119-2008 Household and similar electrical appliances - Performance - Hard water for testing, and the following main technical changes have been made with respect to GB/T 23119-2008.
——The name of the standard is changed from Household and similar electrical appliances - Performance - Hard water for testing to Household and similar electrical appliances - Water for performance testing.
——In Chapter 1, the original 3 types of standard water are increased to 4 types, from soft to very hard, divided according to hardness, conductivity and alkalinity.
——Chapter 2 adds normative reference documents related to the determination of conductivity, alkalinity and pH value.
——Chapter 3 adds the definition of alkalinity and conductivity, as well as the symbols, units and definitions of alkalinity, conductivity and hardness.
——The name of Chapter 4 is changed to "Measurement and Accuracy", with additional requirements for hardness, alkalinity and conductivity.
——The name of Chapter 5 is changed to "standard water", which defines four different types of water and puts forward additional requirements.
——The overall structure of Chapter 6 is adjusted, and preparation of water method A is no longer retained; preparation of water method C3 is added, taking alkalinity and conductivity into account, which is an important content of this standard adjustment.
——Annex A, the hardness classification of test water is changed from the original level 3 to level 4.
This standard is identical to IEC 60734:2012 (Ed4.0) Household electrical appliances - Performance - Water for testing by means of translation.
The Chinese documents consistent and corresponding with the normative international documents in this standard are as follows:
——GB/T 7477-1987, Water quality; Determination of the sum of calcium and magnesium; EDTA titrimetric method (eqv ISO 6059:1984)
——GB/T 15451-2006, Industrial circulating cooling water - Determination of total and composite alkalinity (ISO 9963-1:1994, MOD)
——GB/T 22592-2008, Water treatment reagent - General rules for the determination of pH (ISO 10523:1994, NEQ)
The following editorial changes have been made in this standard:
——The standard name is modified.
This standard was proposed by China National Light Industry council.
This standard is under the jurisdiction of National Technical committee on Household Electric Appliances of Standardization Administration of China (SAC/TC 46).
The previous edition of this standard is as follows:
——GB/T 23119-2008.
Introduction
This standard describes a variety of preparation methods for standard water used in household appliances tests to avoid the influence of water quality on the reproducibility of relevant test results.
This standard describes two methods, A and B, for preparing water of three different hardnesses. The experience of the application of these methods shows that for some purposes, if the cost is very expensive, or these are not suitable for producing large amounts of hard water, these methods do not have to be strictly implemented; in addition, some given water hardness does not meet the performance standard requirements, in such cases, Using the given replenishment methods C1 and C2, it is allowed to use softened water instead of tap water.
Method A is used to prepare hard water that generally meets the hardness requirements. The salt for hardening is prepared by dissolving carbon dioxide bubbles into demineralized water.
Method B is prepared in a similar manner, but other types of salt are used, and the salt should be dissolved without the use of carbon dioxide. compared with the method A, the preparation result of this method will generate excess ions. Both method A and method B can obtain the required temporary hardness or permanent hardness of hard water.
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.
Household and similar electrical appliances - Water for performance testing
1 Scope
This 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 referenced document is indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (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 terms and 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
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
For the purposes of this document, the following symbols apply.
Symbol Unit Definition
A0 mmol/L initial alkalinity
Areq mmol/L target alkalinity
c0 (Fe) mg/L initial iron content
cmax (Fe) mg/L Maximum iron content
c0 (Cu) mg/L initial copper content
cmax (Cu) mg/L Maximum copper content
c0 (Mn) mg/L initial Manganese content
cmax (Mn) mg/L Maximum Manganese content
c0 (Cl-) mmol/L initial chloride content
cmax (Cl-) mmol/L Maximum chloride content
cond0 μS/cm initial conductivity
condreq μS/cm target conductivity
dil — dilution factor
dilmin — lowest possible dilution factor that allows the preparation of water to meet all requirements
dilmia(h, A.cond) — lowest possible dilution factor that allows the preparation of water to meet the total hardness, alkalinity and conductivity requirements
dilmin(Fe) — lowest possible dilution factor that allows the preparation of water to meet the maximum iron content requirement
dilmin (Cu) — lowest possible dilution factor that allows the preparation of water to meet the maximum copper content requirement
dilmin (Mn) — lowest possible dilution factor that allows the preparation of water to meet the maximum manganese content requirement
— lowest possible dilution factor that allows the preparation of water to meet the maximum chloride content requirement
kA — constants
kH — constants
h0 — initial total hardness
hreq mmol/L target total hardness
additionA mmol/L quantity of solution to be added to reach required alkalinity
additionH mL quantity of solution to be added to reach required total hardness
additioncond mL quantity of solution to be added to reach required conductivity
4 Measurements and accuracy
Measurements according to this Standard shall comply with the following specifications in Table 1:
Table 1 Measurement specifications
Parameter Unit Minimum accuracy Additional requirements and remarks
Total hardness mmol/L ±2% See ISO 6059 for specifications of such determination.
Alkalinity
mmol/L
±5% The alkalinity is measured as the concentration of (HCO3-). If 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%
at 20℃ See ISO 7888 for specifications of such determination.
pH — ±0.05 The accuracy requirement shall be met over a temperature
range of 15 °C to 25 °C.
content of iron, copper, manganese or chloride
—
— The requirements for these parameters are maximum content 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.
Foreword I
Introduction III
1 Scope
2 Normative references
3 Terms, Definitions and Symbols
4 Measurements and accuracy
5 Standard water
6 Preparation of standard water
7 Storage of standard water
8 Checking
Annex A (Informative) Water hardness - conversion table