SIST-TS CLC/TS 50677:2019
(Main)Clothes washing machines and washer-dryers for household and similar use - Method for the determination of rinsing effectiveness by measurement of the surfactant content at textile materials
Clothes washing machines and washer-dryers for household and similar use - Method for the determination of rinsing effectiveness by measurement of the surfactant content at textile materials
This Technical Specification provides a method for the evaluation of the rinsing effectiveness of household clothes washing machines, washer dryers and commercial washing machines. The amount of residual linear alkylbenzene sulfonate surfactant (LAS) extracted from the unstained test swatches of the strips used in the washing performance test is determined. This is accomplished by measuring the ultraviolet (UV) light absorbance at the wavelength particular to LAS, a key ingredient of the detergent.
Assuming a fixed linear relationship between LAS amount and quantity of detergent mixture and using a concentration versus absorbance curve developed as part of this procedure, the absorbance values are then converted into detergent concentrations, which together with the test solution mass data, yields detergent quantities. This assumption is done, because in the frame of this test it is not possible to determine the exact amount of LAS involved, even in the concentration curves, but only the amount of detergent used.
On the textiles, this linear relationship is not given, but it is nevertheless used to express the amount of LAS as determined by UV light absorbance measurements in terms of a detergent amount.
Using a concentration versus absorbance curve developed as part of this procedure, the absorbance values can then be converted into detergent concentrations, which together with the test solution mass data, yields detergent quantities.
Waschmaschinen und Waschtrockner für den Hausgebrauch und ähnlichen Gebrauch - Methode zur Bestimmung der Spülwirkung durch Messung des Tensidgehalts an Textilien
This Technical Specification provides a method for the evaluation of the rinsing effectiveness of household clothes washing machines, washer dryers and commercial washing machine. The amount of residual detergent extracted from the unstained swatches of the strips used in the washing performance test is determined. This is accomplished by measuring the ultraviolet light absorbance at the wavelength particular to linear alkylbenzene sulfonate surfactant, a key ingredient of the detergent with a known linear relationship to the quantity of detergent mixture.
Using a concentration versus absorbance curve developed as part of this procedure, the absorbance values can then be converted into detergent concentrations, which together with the test solution mass data, yields detergent quantities.
NOTE: The precision and bias of this measurement is under investigation.
Machines à laver le linge et machines à laver et à sécher pour usages domestiques et analogues - Méthode pour la détermination de l'efficacité de rinçage par la mesure de la teneur en tensioactifs des matières textiles
La présente Spécification Technique fournit une méthode pour l'évaluation de l'efficacité de rinçage des machines à laver le linge à usage domestique, des machines lavantes-séchantes et des machines à laver à usage commercial. La quantité d'alkylbenzènesulfonate linéaire tensioactif (LAS) résiduel extraite à partir des pièces d'essai non salies des bandes utilisées pour l'essai d'aptitude à la fonction de lavage est déterminée, en mesurant l'absorbance de la lumière ultraviolette (UV) à la longueur d'onde spécifique du LAS, un ingrédient essentiel du détergent.
En prenant pour hypothèse une relation linéaire fixe entre la quantité de LAS et la quantité de mélange détergent et en utilisant une concentration en fonction de la courbe d'absorbance déterminée dans le cadre de cette procédure, les valeurs d'absorbance sont ensuite converties en concentrations de détergent qui, combinées aux données relatives à la masse de la solution d'essai, indiquent les quantités de détergent. Cette hypothèse est admise, car il n'est pas possible dans le cadre de cet essai de déterminer la quantité exacte de LAS employée, même avec les courbes de concentration, mais uniquement la quantité de détergent utilisée.
Sur les textiles, cette relation linéaire n'est pas indiquée, mais elle est néanmoins utilisée pour exprimer la quantité de LAS déterminée par les mesures d'absorbance de la lumière UV pour une quantité de détergent.
En utilisant une concentration en fonction de la courbe d'absorbance déterminée dans le cadre de cette procédure, les valeurs d'absorbance peuvent ensuite être converties en concentrations de détergent qui, combinées aux données relatives à la masse de la solution d'essai, indiquent les quantités de détergent.
Pralni in pralno-sušilni stroji za gospodinjsko in podobno uporabo - Metoda za ugotavljanje učinkovitosti izpiranja z merjenjem tenzidov na tekstilu
Ta tehnična specifikacija ponuja metodo za vrednotenje učinkovitosti izpiranja gospodinjskih pralnih strojev, pralno-sušilnih strojev in komercialnih pralnih strojev. Določi se količina ostankov linearnega alkilbenzensulfonatnega tenzida (LAS), izluščenega iz nepobarvanih preskusnih vzorcev trakov, uporabljenih pri preskusu učinkovitosti pranja. To se doseže z merjenjem vpijanja ultravijolične (UV) svetlobe pri valovni dolžini, značilni za linearni alkilbenzensulfonatni tenzid, ki je ključna sestavina detergenta.
Če predpostavimo, da je med količino linearnega alkilbenzensulfonatnega tenzida in količino mešanice detergenta fiksno linearno razmerje ter če uporabimo krivuljo koncentracije v primerjavi z vpojnostjo, ki je pripravljena kot del tega postopka, se vrednosti vpojnosti nato pretvorijo v koncentracije detergenta, ki skupaj s podatki o masi preskusne raztopine zagotavlja podatke o količinah detergenta. Ta predpostavka se uporabi, ker v okviru preskusa ni mogoče določiti natančne količine vpletenega linearnega alkilbenzensulfonatnega tenzida, niti na koncentracijskih krivuljah, ampak zgolj količino uporabljenega detergenta.
Na tkaninah to linearno razmerje ni podano, vendar se kljub temu uporablja za izražanje količine linearnega alkilbenzensulfonatnega tenzida, ugotovljene z meritvami vpijanja UV-svetlobe, na podlagi količine detergenta.
Če uporabimo krivuljo koncentracije v primerjavi z vpojnostjo, ki je pripravljena kot del tega postopka, se vrednosti vpojnosti nato pretvorijo v koncentracije detergenta, ki skupaj s podatki o masi preskusne raztopine zagotavlja podatke o količinah detergenta.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2019
Pralni in pralno-sušilni stroji za gospodinjsko in podobno uporabo - Metoda za
ugotavljanje učinkovitosti izpiranja z merjenjem tenzidov na tekstilu
Clothes washing machines and washer-dryers for household and similar use - Method
for the determination of rinsing effectiveness by measurement of the surfactant content
at textile materials
Waschmaschinen und Waschtrockner für den Hausgebrauch und ähnlichen Gebrauch -
Methode zur Bestimmung der Spülwirkung durch Messung des Tensidgehalts an
Textilien
Machines à laver le linge et machines à laver et à sécher pour usages domestiques et
analogues - Méthode pour la détermination de l'efficacité de rinçage par la mesure de la
teneur en tensioactifs des matières textiles
Ta slovenski standard je istoveten z: CLC/TS 50677:2019
ICS:
97.060 Aparati za nego perila Laundry appliances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL SPECIFICATION CLC/TS 50677
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2019
ICS 97.060
English Version
Clothes washing machines and washer-dryers for household and
similar use - Method for the determination of rinsing
effectiveness by measurement of the surfactant content at textile
materials
Machines à laver le linge et machines à laver et à sécher Waschmaschinen und Waschtrockner für den
pour usages domestiques et analogues - Méthode pour la
Hausgebrauch und ähnliche Zwecke - Verfahren zur
détermination de l'efficacité de rinçage par la mesure de la Bestimmung der Spülwirkung durch Messung des
teneur en tensioactifs des matières textiles Tensidgehalts an Textilien
This Technical Specification was approved by CENELEC on 2018-12-31.
CENELEC members are required to announce the existence of this TS in the same way as for an EN and to make the TS available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TS 50677:2019 E
Contents Page
European foreword .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
4 Symbols and abbreviated terms .6
4.1 The variables for Rinse Effectiveness calculations are defined as: .6
4.2 Symbols relating to Annex A .7
5 Requirements .7
6 Test method .8
6.1 Equipment and materials .8
6.1.1 Climate chamber .8
6.1.2 Ultraviolet (UV) spectrophotometer .8
6.1.3 Quartz cuvette .8
6.1.4 Cuvette rack .8
6.1.5 Orbital shaker .8
6.1.6 Scale for weighing detergent and samples .8
6.1.7 Weigh bowl .9
6.1.8 Volumetric flask .9
6.1.9 Graduated cylinder, 100 ml .9
6.1.10 Magnetic stirrer .9
6.1.11 Magnetic stir bar .9
6.1.12 Pipette .9
6.1.13 Disposable glass pipettes (e.g. Pasteur pipettes) .9
6.1.14 Pipette bulbs, 2 ml or greater .9
6.1.15 Sample bottle with cap (for test swatch extraction) .9
6.1.16 Laboratory wipes .9
6.1.17 Distilled water .9
6.1.18 Squirt bottle . 10
6.1.19 Funnel . 10
6.1.20 Reference detergent A* base powder . 10
6.2 Preparation of equipment . 10
6.2.1 UV spectrophotometer check . 10
6.2.2 Cleanliness . 10
6.2.3 Cuvette filling and cleaning . 10
6.2.4 Checking the quality of the distilled water . 10
6.2.5 Cuvette matching . 13
6.3 Procedure . 13
6.3.1 Detergent concentration curve . 13
6.3.2 Test run procedure . 14
6.3.3 Acquiring samples. 14
6.3.4 UV Absorbance Measurements . 15
6.4 Expression of results . 16
6.4.1 Rinsing Effectiveness . 16
6.4.2 Rinse Evenness . 18
7 Data to be reported . 18
Annex A (normative) Procedure for Determining Detergent Concentration Curve . 19
General approach . 19
A.1
A.2 IEC-A* base detergent sampling . 19
A.3 Distilled Water . 19
A.4 Preparation of Stock 1 solution (IEC-A* base powder detergent) . 19
A.4.1 Sample Weighing . 19
A.4.2 Mix the Sample . 19
A.4.3 Stock 1 Calculation . 20
A.5 Preparation of Stock 2 . 20
A.5.1 Mix the Sample . 20
A.5.2 Stock 2 Calculation . 20
A.6 Preparation of Working Standards . 21
A.6.1 Mix the Solutions . 21
A.6.2 Working Standard Calculations . 21
A.7 Measure the Absorbance of the Working Standard Solutions . 22
A.8 Calculations . 23
A.8.1 Initial Treatment of the Data . 23
A.8.2 Single sample data (per detergent sample) . 23
A.8.3 Combined sample data (all detergent samples) . 23
Annex B (normative) IEC-A* base powder detergent sampling . 24
B.1 Purpose . 24
B.2 Devices and Materials . 24
B.3 Sampling procedure . 24
Annex C (informative) Acquiring samples using a dispenser . 28
C.1 General . 28
C.2 Calibration of the dispenser . 28
C.2.1 General . 28
C.2.2 Priming . 28
C.2.3 Setting the volume . 28
C.2.4 Calibration: . 28
C.2.5 Calculation: . 29
C.3 Acquiring samples (with dispenser) . 29
Annex D (informative) Quartz cuvette and glassware cleaning and handling . 30
D.1 Purpose . 30
D.2 Cuvettes . 30
D.3 General Cleaning . 30
D.4 Periodic Glass Cleaning . 31
D.4.1 General . 31
D.4.2 Standard Glassware Cleaning Solutions . 31
Annex E (informative) Uncertainty of the test method . 32
Annex F (informative) Reduction of the test effort . 33
Annex G (normative) Test report – Data to be recorded . 34
G.1 General . 34
G.2 Data for test washing machine . 34
G.3 Data, parameters and results for the test series . 35
G.4 Example of calibration data collection (including calculation) . 36
G.5 Example of data collection for measurement . 38
Bibliography . 39
European foreword
This document (CLC/TS 50677:2019) has been prepared by CLC/TC 59X "Performance of household and
similar electrical appliances".
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
1 Scope
This Technical Specification provides a method for the evaluation of the rinsing effectiveness of household
clothes washing machines, washer dryers and commercial washing machines. The amount of residual
linear alkylbenzene sulfonate surfactant (LAS) extracted from the unstained test swatches of the strips
used in the washing performance test is determined. This is accomplished by measuring the ultraviolet
(UV) light absorbance at the wavelength particular to LAS, a key ingredient of the detergent.
Assuming a fixed linear relationship between LAS amount and quantity of detergent mixture and using a
concentration versus absorbance curve developed as part of this procedure, the absorbance values are
then converted into detergent concentrations, which together with the test solution mass data, yields
detergent quantities. This assumption is done, because in the frame of this test it is not possible to
determine the exact amount of LAS involved, even in the concentration curves, but only the amount of
detergent used.
On the textiles, this linear relationship is not given, but it is nevertheless used to express the amount of
LAS as determined by UV light absorbance measurements in terms of a detergent amount.
Using a concentration versus absorbance curve developed as part of this procedure, the absorbance
values can then be converted into detergent concentrations, which together with the test solution mass
data, yields detergent quantities.
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.
EN 60456:2016, Clothes washing machines for household use — Methods for measuring the performance
(IEC 60456)
3 Terms and definitions
No terms and definitions are listed in this document.
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 http://www.iso.org/obp
4 Symbols and abbreviated terms
4.1 The variables for Rinse Effectiveness calculations are defined as:
Asp average absorbance
a
Asp 1)
avg,j
average net absorbance of the sample j
Asp 1)
i net absorbance for specimen i
Asp 1)
i,223
absorbance reading at 223 nm for specimen i
Asp
i,330 1)
absorbance reading at 330 nm for specimen i
Asp 1)
m peak absorbance at wavelength m
1)
Care shall be taken in the calculations of Clause 6, as these variables are depending on additional
parameters, e.g. index of the sample, swatch or test run.
Asp 1)
r,m relative peak absorbance at wavelength m
Cs 1)
j concentration of detergent in sample j
Ds 1)
j mass of detergent recovered from sample j
Dsw
avg,l average ratio of mass of detergent recovered per gram
of test swatch from the test run l
Dsw 1)
k ratio of mass of detergent of test swatch k
DL ratio of mass of detergent of test run l
l
i, j, k and l index of specimens, samples, swatches and test run
m slope of the detergent concentration curve
n number of cuvettes, specimens, samples, swatches or
2)
test runs
R
Rinse Effectiveness (average of all test runs)
Re Rinse Evenness Score
S standard deviation of the Rinse Effectiveness
R
S standard deviation of the ratio of mass of detergent
r,l
recovered per gram of test swatch for test run l
Wsw 1)
k weight of test swatch k
Ws 1)
j weight of water in sample j
4.2 Symbols relating to Annex A
b intercept of the detergent concentration curve
CWSS detergent concentration of Working Standard Solution
m mass of detergent
det
m slope of the detergent concentration curve
m mass of transferred Stock 1 solution
m mass of transferred Stock 2 solution
St concentration of Stock 1 solution
St concentration of Stock 2 solution
y absorbance value of the sample
x concentration of the detergent in the sample
5 Requirements
(Not available in this document.)
2)
Care shall be taken, as numbers of different parameters are different.
6 Test method
6.1 Equipment and materials
NOTE This materials list is additional to the materials list in EN 60456:2016, 5.4.
6.1.1 Climate chamber
The ambient temperature and relative humidity in the climate chamber shall be maintained at:
— temperature: (20 ± 2) °C
— relative humidity: (65 ± 5) %.
6.1.2 Ultraviolet (UV) spectrophotometer
The absorption of the ultraviolet light shall be measured with a ultraviolet spectrophotometer with the
following specifications:
— wavelength range: 190 nm to 1100 nm
— spectral bandwidth: ≤ 1 nm
— wavelength accuracy (at D peak 656,1 nm): - 0,2 to 0,2 nm
— wavelength repeatability (10 measurements at 656,1 nm, slit width 1 nm): - 0,05 to 0,05 nm
— photometric range: - 0,1 to 3,0 A
— photometric accuracy (UV with K Cr O , Ph.Eur. at 1 A): - 0,02 to 0,02 A
2 2 7
— photometric repeatability (10 measurements with K Cr O , Ph.Eur. at 1 A): - 0,002 to 0,002 nm.
2 2 7
The spectrophotometer has to be calibrated regularly according to the manufacturer’s specification.
6.1.3 Quartz cuvette
The cuvettes to be used for the measurement of the ultraviolet absorption shall be rectangular with a path
length of 10 mm and be made from quartz
6.1.4 Cuvette rack
(Not specified in this document.)
6.1.5 Orbital shaker
The device for the extraction of the linear alkylbenzene sulfonate shall be an orbital shaker. The orbital
shaker shall have a device for securing sample bottles on it.
Orbit: 4 mm to 20 mm
Shaker speed: ≥ 350 r/min
NOTE The speed of the shaker can be checked by a tachometer, either optical by light beam reflection or
mechanical by a magnetic sensor. For details it is advised to refer to the manufacturer’s specification.
6.1.6 Scale for weighing detergent and samples
Minimum specification: 0 to 150 g range with
Minimum resolution: 0,001 g
Accuracy: ± 0,002 g
6.1.7 Weigh bowl
(Not specified in this document.)
6.1.8 Volumetric flask
For the preparation of the working standards for calibration volumetric flasks with a volume of 100 ml and
1 000 ml shall be used.
6.1.9 Graduated cylinder, 100 ml
(Not specified in this document.)
6.1.10 Magnetic stirrer
(Not specified in this document.)
6.1.11 Magnetic stir bar
Small, medium and large stir bars shall be used.
6.1.12 Pipette
Pipette of volume 1, 2, 5, 10 and 25 ml shall be used.
6.1.13 Disposable glass pipettes (e.g. Pasteur pipettes)
Disposable glass pipettes without cotton stoppers, non sterile and with a volume of 2 ml or greater shall be
used for transferring the extract to the cuvettes.
NOTE A transfer pipette with disposable plastic tips can be used in place of glass pipettes after correlation tests.
6.1.14 Pipette bulbs, 2 ml or greater
(Not specified in this document.)
6.1.15 Sample bottle with cap (for test swatch extraction)
For the extraction of the test swatches plastic bottles with cap made from high-density polyethylene with a
volume of 125 ml and a diameter of 5 cm shall be used.
6.1.16 Laboratory wipes
(Not specified in this document.)
6.1.17 Distilled water
All water used for extractions, dilutions and the preparation of calibration standards shall meet the following
criteria:
Conductivity at 25 °C: ≤ 1 µS/cm.
Net absorbance (223 nm to 330 nm): - 0,002 to 0,002 A.
Absorbance curve spectrum 200 nm to 350 nm: no relative peak absorbance greater than ± 0,002 A in the
range between 223 nm to 330 nm.
The procedure for calculating these values is given in 6.2.4.
NOTE Water prepared by methods other than distillation having equivalent specifications can be used instead of
distilled water.
6.1.18 Squirt bottle
Material: high-density polyethylene
6.1.19 Funnel
(Not specified in this document.)
6.1.20 Reference detergent A* base powder
The detergent used for calibration is IEC-A* as described in EN 60456:2016. Only the base powder IEC-A*
shall be used for the determination of the calibration curve. The calibration shall be done with the batch of
detergent used for washing.
NOTE This document only refers to IEC-A* as detergent. It is possible to use other detergents than IEC-A*. For
all cases the calibration shall be done with the detergent used for washing.
6.2 Preparation of equipment
(Not specified in this document.)
6.2.1 UV spectrophotometer check
Turn on the UV spectrophotometer. It should be run approximately 30 min before measurements (refer to
the manufacturer’s specification).
If the instrument has a built-in self-check function, perform the self-check once a day before measuring
data. This may be included in the calibration report.
6.2.2 Cleanliness
All materials that come in contact with detergent, distilled water, Stock 1, Stock 2 or the working standard
solutions shall be cleaned and thoroughly rinsed with distilled water then dried before use. A professional
laboratory dishwasher may be used for this purpose.
6.2.3 Cuvette filling and cleaning
The cuvettes should be handled by the opaque sides only. Do not touch the clear sides of the cuvettes.
To avoid air bubbles, fill by running the solution down the side of the cuvette. Fill cuvettes without soiling or
wetting the exterior measuring surface. If air bubbles are present, eliminate them by holding the cuvette at
a slight angle and tapping the opaque side as many times as necessary to release the bubbles.
To prevent liquid from running down the cuvette surface after discharging, place the cuvette head first on a
clean position of a lint-free tissue for some seconds. Replace the tissue from time to time if no clean
position is left.
If a cuvette gets wet on the outside, clean the cuvette and re-check with distilled water. Do not only
wipe/dry the cuvette surface with a tissue. Remaining residues in the UV-area are not visible.
NOTE See Annex D (informative), Quartz cuvette and glassware cleaning and handling.
6.2.4 Checking the quality of the distilled water
6.2.4.1 General
Take a spectrum (200 nm to 350 nm) of the distilled water used for testing as described in 6.2.4.2 f).
If
a) the calculated net absorbance value (223 nm to 330 nm) is greater than ± 0,002 A
or
b) any relative peak absorbance value in the range between 223 nm to 330 nm is greater than ± 0,002 A
Check the spectrum for abnormality and repeat this section with a different batch of distilled water. Such
water is likely to contain impurities which could interfere with this test method and lead to unreliable results.
6.2.4.2 Spectrum from 200 nm to 350 nm
a) Start Spectrophotometer and wait for warm up
b) Use only one cuvette
c) Place a DRY and CLEAN and EMPTY cuvette into the position for zeroing the cuvette. The positioning
of the cuvette may vary according to the type of spectrophotometer used:
— for double beam devices, place the cuvette in the measuring position and leave the
reference/blank position empty;
— for single beam devices with a carrousel, place the cuvette in the reference/blank position.
d) Zero the device (baseline correction)
e) Fill the cuvette with distilled water (rinse twice, keep the third for measurement), place cuvette into the
measuring position, leave the reference/blank position empty if applicable.
f) Run a spectrum with the following settings (or the closest available on the spectrophotometer used):
— range: 200 nm to 350 nm
— bandwidth: 1 nm
— speed: 10 nm/s
— integration time: 0,1 s
— switch light source (UV to visual light): ≥ 360 nm
An example of a typical spectrum is given in Figure 1, Example spectrum of distilled water.
Figure 1 — Example spectrum of distilled water
6.2.4.3 Calculation of net absorbance (223 nm - 330 nm)
For each specimen i calculate the net absorbance Asp
i
Asp = Asp – Asp
i i,223 i,330
where
Asp is the absorbance reading at 223 nm for specimen i
i,223
Asp is the absorbance reading at 330 nm for specimen i
i,330
i is index of the specimen.
6.2.4.4 Calculation of relative peak absorbance
Detect all peaks (minimum and maximum) in the range between 223 nm to 330 nm with a peak threshold
value ≥ 0,0002 A.
For each specimen i, calculate the average absorbance Asp
a
Asp = (Asp + Asp ) / 2
a i,223 i,330
where
Asp is the absorbance reading at 223 nm for specimen i
i,223
Asp is the absorbance reading at 330 nm for specimen i
i,330
i is index of a specimen.
For all peaks with wavelength m, calculate the relative peak absorbance Asp
r,m
Asp = Asp – Asp
r,m m a
where
Asp is the peak absorbance at wavelength m
m
Asp is the average absorbance.
a
Example for the calculation of the net absorbance of specimen i
Asp = - 0,007 A
i,223
Asp = 0,007 A
i,330
Calculate:
Asp = - 0,007 A – 0,007 A
i
Asp = - 0,014 A
i
Example for the calculation of the relative peak absorbance of specimen i
Asp = - 0,007 A
i,223
Asp = 0,007 A
i,330
Asp = Asp = - 0,013 A (highest peak at 240 nm)
m 240
Calculate:
Asp = (Asp + Asp ) / 2
a i,223 i,330
Asp = (- 0,007 A + 0,007 A) / 2
a
Asp = 0,000 A
a
Asp = Asp – Asp
r,240 240 a
Asp = - 0,013 A – 0,000 A
r,240
Asp = - 0,013 A
r,240
6.2.5 Cuvette matching
Before measuring samples, cuvette matching is verified by filling all cuvettes with distilled water (rinse
twice, keep the third for measurement). Measure all cuvettes (including blank) against empty blank position
in spectrophotometer. Record absorbance values (223 nm, 330 nm). Repeat this step 3 times for each of
the cuvettes. Always place the clear sides of the cuvette in the same direction into the cuvette holder (e.g.
marking of the cuvette always to the beam side). Use this direction for all measurements.
Calculate the average net absorbance value (223 nm to 330 nm) for the three readings per cuvette. If the
range of the averaged values of all cuvettes is greater than 0,002 A repeat this section with clean or new
cuvettes. Only use cuvettes with an averaged net absorbance value smaller or equal to 0,002 A.
6.3 Procedure
(This section is written for washing machines up to now. Washer dryers and commercial washing
machines should be tested in a similar way. The description will be updated at a later time.)
6.3.1 Detergent concentration curve
6.3.1.1 General
The purpose of the detergent concentration curve is to provide an equation relating the amount of IEC-A*
detergent to the absorbance value obtained from a water sample containing IEC-A* base powder
detergent. This is accomplished by measuring the UV absorbance at the wavelength particular to LAS
(linear alkylbenzene sulfonate, surfactant), a key ingredient of the IEC-A* base powder detergent with an
assumed fixed linear relationship to the quantity of the IEC-A* detergent. This assumption is done,
because in the frame of this test it is not possible to determine the exact amount of LAS involved, even in
the concentration curves, but only the amount of detergent used. On the textiles, this linear relationship is
not given, but it will nevertheless be used to express the amount of LAS as determined by UV light
absorbance measurements in terms of a detergent amount.
6.3.1.2 Frequency for Determining Detergent Concentration Curve
A detergent concentration curve should be determined for each new batch of IEC-A* base powder
detergent used. It should also be redone when any significant changes have been made in the system
(new location, new instrument, etc.) or when questions about data quality have arisen (new analyst,
suspicious data, etc.).
6.3.1.3 Procedure for Determining Detergent Concentration Curve
See Annex A (normative), Procedure for Determining Detergent Concentration Curve.
6.3.2 Test run procedure
6.3.2.1 Prepare the load for performance test according to IEC / EN
See EN 60456:2016, Clause 6.
6.3.2.2 Perform the test run as specified in Clause 8 of EN 60456:2016 with the following
changes
Do not iron the white unsoiled test swatch. Label the stain strips along the edge of the sebum stain. Do not
add markings to the white unsoiled test swatch.
6.3.3 Acquiring samples
Samples shall be read on the day of extraction. Do not expose sample bottles to direct sunlight (due to
warming up).
a) After completion of the test run, remove the white unsoiled test swatch from each stain strip by cutting
close to the sewn seam. Use tweezers to handle the test swatch. Clean the tweezers with distilled
water between each test run. Remove any loose threads. Ensure that the test swatch does not come
in contact with detergent residues while removing the test swatch and until the test swatch is placed in
the climate chamber. Do not touch the test swatch.
b) Place the test swatches in the climate chamber for minimum 16 h. Use tweezers to handle the test
swatches.
Ensure that each test swatch is completely exposed to the conditioned air. This can be done by hang
drying using marked clothes-pegs. Do not place the test swatch on a solid surface. All objects coming
in contact with the test swatches shall be clean and free from detergent residues. Take care not to mix
test swatches from different test runs, the test swatches are not labelled.
c) After conditioning in the climate chamber put each test swatch while in the climate chamber in a
separate labelled plastic bag for protection from humidity. Use tweezers to handle the test swatches.
d) For each test swatch label a new sample bottle with the test run information and remove the cap from
the bottle.
e) Place the sample bottle on the scale and tare (“zero”) the scale.
f) Measure approximately 100 ml of distilled water (23 ± 2) °C in a graduated cylinder.
g) Remove the sample bottle from the scale and add the water to the bottle. Put the sample bottle back
on the scale and record the mass Ws of the water to 3 decimals.
i
h) Repeat step d) to g) for each test swatch.
i) Put a plate on the scale and tare (“zero”) the scale.
j) Put a test swatch on the plate and record the mass Wsw of the test swatch for the corresponding test
k
run number to 3 decimals. Use tweezers to handle the test swatch.
k) Repeat step i) to j) for each test swatch.
l) Insert the test swatches into the corresponding sample bottles without folding, close the cap and put
the bottles on the shaker. Use tweezers to handle the test swatches.
m) Place the sample bottles on the shaker and secure it, utilizing a retention rack or similar means.
n) Shake at 350 r/min for 60 min.
o) After shaking remove all test swatches with dry tweezers within 5 min and discard. Do not squeeze the
water out of the test swatches as they are removed. Close caps on sample bottles.
p) Take UV absorbance measurements of the water samples per sub-clause 6.3.4.
NOTE Instead of weighing the water into the sample bottles the procedure can be simplified and clearly
accelerated by using a dispenser to fill a specific volume of water. See Annex C.
6.3.4 UV Absorbance Measurements
6.3.4.1 Preparation of Equipment
Prepare equipment used for UV measurement as described in 6.1.20.
Fill cuvettes with distilled water to the fill line. Zero cuvettes against the blank cuvette in the UV
spectrophotometer.
Select a new disposable glass pipette for each sample to be measured.
6.3.4.2 Preparation of Blank
a) Rinse a glass pipette by drawing in 2 ml of distilled water and expel. Repeat this step one more time.
b) Refill the pipette.
c) Rinse a cuvette twice with distilled water and refill the pipette.
d) Dispense distilled water into the cuvette to the fill line and place in the spectrophotometer in the
position marked for a “blank”.
NOTE One blank can be used for all testing performed at one time (retain the blank in the spectrophotometer). It
is advised to check the blank periodically for air bubbles and discard it if bubbles are present.
6.3.4.3 Preparation and reading of Specimens from Extracted Water Samples
Recap the sample bottles by only placing the caps on the bottles. Place all sample bottles at the workplace
near to the measuring position/device in a way that the measured samples can be taken out without
moving the bottles.
Let the sample bottles rest for 30 min to allow sedimentation.
Take out the samples from the upper third of the liquid level in the sample bottles.
a) Select a sample bottle and do not shake or move the bottle.
b) Rinse a glass pipette by drawing in 2 ml of the sample and expel. Repeat this step one more time.
c) Refill the pipette.
d) Rinse a cuvette twice with the sample and refill the pipette.
e) Dispense sample into the cuvette to the fill line.
f) Place the cuvette in the spectrophotometer, always positioning the same clear side facing the light
beam.
g) Measure and record the UV absorbence Asp and Asp of the specimens at 223 nm and 330 nm
i,223 i,330
wavelengths to 4 decimals.
h) Repeat steps e) to f) for 3 cuvettes or steps e) to f) for 3 measurements if only one cuvette is used for
sample measurement.
i) Recap the sample bottle and save until readings are analyzed.
NOTE If more than one cuvette is used, it is advised to keep the cuvettes in the same position and direction on
the spectrophotometer carousel throughout the test.
j) Repeat steps 6.3.4.2 and 6.3.4.3 for the remaining sample bottles.
NOTE If an absorbance reading exceeds the limit of the calibration curve data, it is essential that the sample is
diluted and measured again. The calculated concentration is then adjusted according to the dilution factor. For
example, if the calculated concentration of a 50 % diluted sample is 150 mg/l, the undiluted sample would have a
concentration of 150 mg/l x 2 = 300 mg/l.
6.4 Expression of results
6.4.1 Rinsing Effectiveness
Using the detergent concentration curve established in Annex A, calculate the rinsing effectiveness with
the following formulae. An explanatory calculation spreadsheet is shown in Annex G.
Calculations:
a) For each specimen i, calculate the net absorbance Asp :
i
Asp = Asp – Asp
i i,223 i,330
where
Asp is the net absorbance reading at 223 nm for speciem i;
i,223
Asp is the net absorbance reading at 330 nm for speciem i.
i,330
b) For each sample j, calculate the average net absorbance Asp :
avg,j
n
Asp = Asp
avg, j ∑ i
n
i=1
where
Asp is the net absorbance for each specimen i, as calculated in a);
i
n is the number of cuvettes utilized or the number of measurements done for the sample.
c) Concentration of detergent of sample j, expressed in mg/l, Cs :
j
Asp − b
avg, j
Cs =
j
m
where
Asp is the average net absorbance for sample j, as calculated in b);
avg,j
b is the intercept of the detergent concentration curve, as calculated in A.8.3 c);
m is the slope of the detergent concentration curve, as calculated in A.8.3 c).
d) Mass of detergent recovered from sample j, expressed in mg, Ds :
j
1 l
Ds= Cs××Ws
j j j
1000 g
where
Cs is the concentration of the detergent in sample j in mg/l, as calculated in c);
j
Ws is the weight of water in sample j in g.
j
e) Ratio of mass of detergent recovered per gram of test swatch k, expressed in mg/g; Dsw :
k
Ds
j
Dsw =
k
Wsw
k
where
Ds is the mass of detergent recovered from sample j in mg, as calculated in d);
j
Wsw is the mass of test swatch k, in g.
k
f) Average ratio of mass of detergent recovered per gram of test swatch from the test run l, expressed in
mg/g, Dsw :
avg,l
n
Dsw = Dsw
avg,l k
∑
n
k=1
where
Dsw
is the ratio of mass of detergent recovered per gram of test swatch k in mg/g, as calculated in e);
k
n is the number of test swatches.
g) Ratio of mass of detergent per kg of load of test run l, expressed in g/kg; DL :
l
DL = Dsw
l avg,l
where
Dsw is the average ratio of mass of detergent recovered per gram of test swatch from the test run l,
avg,l
as calculated in f).
h) Rinse Effectiveness (average ratio of mass of detergent per kg of load of all test runs), expressed in
g/kg, R:
n
R= DL
l
∑
n
l=1
where
DL is the ratio of mass of detergent per kg of load from test run l in g/kg, as calculated in g);
l
n is the number of test runs.
i) Standard deviation of the Rinse Effectiveness expressed in g/kg, S :
R
n
2 1
S DL− R
( )
R l
∑
n−1
l=1
where
DL is the ratio of mass of detergent per kg of load of test run l expressed in g/kg, as calculated in g);
l
R is the Rinse Effectiveness in g/kg, as calculated in h);
n is the number of test runs.
6.4.2 Rinse Evenness
a) Evenness of rinsing for test run l is represented by the standard deviation of the ratio of mass of
detergent recovered per gram of test swatch for the test run, expressed in g/kg, S :
rl,
n
S Dsw− Dsw
( )
r,,l k avg l
∑
n−1
l=1
where
Dsw is the ratio of mass of detergent recovered per gram of test swatch i in g/kg, as calculated in
k
6.4.1 e);
Dsw is the average ratio of mass of detergent recovered per gram of test swatch from the test run l
avg,l
in g/kg, as calculated in 6.4.1 f);
n
is the number of test swatches.
b) An overall evenness is represented by the geometric mean of the standard deviation from all test runs,
expressed in g/kg, Re:
n
Re= S
r,l
∑
n
l=1
where
S
is the standard deviation of the ratio of mass of detergent recovered per gram of test swatch for test
r,l
run l in g/kg, as calculated in a);
n is the number of test runs.
NOTE Additional evaluations might be possible like ratio of removed detergent.
7 Data to be reported
For each test
...
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